Please comment on the proposed Draft Engineering Standard Updates.

13-04-001: Easements

Section 1. Amend Title 13 Engineering Design Standards, Chapter 13-04: Easements and Rights-of-Way, Division 13-04-001: Easements, Section 13-04-001-0003: Types, as follows:

A.    Typical easement purposes are water, sewer, drainage, public utility, sidewalk, walkways, bike paths, urban trails, open space, slope, temporary turnaround, public service access, and temporary construction easements. However, any purpose agreed upon by both parties will constitute valid use. A vehicular no-access restriction may be required by the City, where vehicular access is not appropriate for safety or legal reasons.

B.    More than one (1) type of easement may occupy the same ground, but if created at different times, the right and use by the senior grant may not be interfered with by the junior; nor can any easement be used for a purpose other than that recited in the grant.

1C.    The grantor may make use of the land subject to the easement but must not interfere with the particular easement use or access thereto.

2D.    The land owner grantor or successor must allow the authorized utility company or City representative access to any piping and/or appurtenances facilities that lie within the public utility easement.

a1.    Access is defined as the ability to walk drive ordinary construction equipment to the piping and/or appurtenance facility.

(1)2.    In the event that a fence or wall is authorized within the easement, no access is available from the installation of a non-edifice, a gate of sufficient width to allow access by ordinary construction equipment, four (4) feet, zero (0) inches minimum in width, may be required to be installed that will allow access.

(2)    The gate may be equipped with a City lock interlocked with a lock from the private resident grantor or successor.

3E.    No permanent structures will be allowed to Permanent obstructions shall not be constructed within, or over the top of, the a public utility or drainage easement except with written permission by the City Engineer. Unauthorized permanent obstructions constructed in an existing public utility or drainage easement shall be removed by the property owner at their expense.

a1.    A permanent structure obstruction is defined as a masonry fence (including trash enclosures), or any part of a building or structure that requires a building permit any wall (including a trash enclosure), any fence that lacks panels that are removable by hand utilizing only simple hand tools, a retaining wall of any height or type (including stacked rock, railroad ties, interlocking masonry, landscape timbers, etc.), sport courts, shade structures, sheds, signage not easily removed with hand tools, or any part of a building or structure that requires a building permit. Trees and other large plantings may be classified as permanent obstructions where such plantings would restrict access within the easement. Exceptions may be granted for certain permanent obstructions particularly at property lines where the easement on both sides of the permanent obstruction is otherwise accessible and the obstruction is generally placed perpendicular to the easement.

b.    A nonpermanent structure is defined as a wooden or chain link fence, curb and gutter, parking lot, landscaping, and buildings or structures that do not require a building permit.

cF.    In the event that theIf a pipe and/or appurtenance facility must be repaired, maintained, or reconstructed, and a nonpermanent structure an allowable feature has been constructed over the easement, the City may require the property owner to remove the nonpermanent structure feature in order for the City to make the repair, perform maintenance, or do reconstruction.

1.    Allowable features that may be placed in easements must not interfere with drainage or access within the easement. Examples of features that ordinarily would be allowable include curb and gutter, pavement, sidewalks, landscaping and light weight fences with removable panels such as wood, iron or certain wire/chain link designs and which are generally perpendicular to the easement (other than drainage easements). Fences are not allowed across drainage easements with open channels. Removable fences with minimum eight (8) foot gates are permitted across drainage easements with underground storm drains.

(1)2.    The property owner may reinstall the structure feature at the owner’s expense.

d.    In the event that the pipe and/or appurtenance must be either repaired, maintained, or reconstructed, and a permanent structure has been constructed over the easement, the permanent structure must be removed by the property owner in order to complete the repair, maintenance, or reconstruction and may not be reinstalled.

eG.    In the event that the structure, either permanent or nonpermanent,If the City requires a property owner to remove a permanent obstruction or allowable feature under parts E or F of this section and the structure is not removed immediatelyin a timely fashion, the City shall have the right to remove the structure and charge the property owner for this effort.

fH.    Private services shall not be installed in a public easement or right-of-way parallel to public utility lines the easement or right-of-way.

CI.    Fences are not allowed across drainage easements with open channels. Removable fences with minimum eight (8) foot gates are permitted across drainage easements with underground storm drains.

I.    No grading other than minor levelling or surface amendments shall be made within any easement that could affect drainage or cover over subsurface facilities without written approval from the City Engineer.

DJ.    An easement does not become void or nonexistent if it ceases to be used for the purpose for which granted unless the grant carries a limitation to that effect.

1.    An easement can be of a temporary nature and cease to exist at the time specified on the grant. One (1)An example would be a construction easement adjoining a permanent easement or a turnaround to be abandoned when the street is extended.

Justification:

The language on what private improvements are allowed in easements needs to be clarified in order to ensure access for maintenance and repairs. The organization of this section caused most of the text to be a sub-part of part B related to multiple easements occupying the same ground. Reorganization will allow the intent to be communicated more coherently. There have been numerous instances where the existing code has been interpreted to allow for the placement of private improvements within easements that prevent access to City facilities for maintenance and repair.

13-06-002: Plans Required

Section 2. Amend Title 13 Engineering Design Standards, Chapter 13-06: Construction Plans, Division 13-06-002: Plans Required, Section 13-06-002-0001.1.1: Modifications, to modify 13-06-002-0001.1.1.A(3) as follows:

3.    A narrative as to why the standard cannot be met. Cost alone is not a justification for modifying standards. Where cost is a consideration, the narrative must include a sealed Engineer’s Estimate of Probable Cost (EOPC) for both the design which meets standard and the cost of the design utilizing the proposed modification.

Justification:

In practice, most modification requests are based in part on cost of complying with the Engineering Standard. The Standards should be adjusted to allow for costs to be considered in modification requests where the costs of compliance would be unreasonably high vs alternatives. 

Section 3. Amend Title 13 Engineering Design Standards, Chapter 13-06: Construction Plans, Division 13-06-002: Plans Required, Section 13-06-002-0003: Format, to modify 13-06-002-0003.A as follows:

A.    All construction plans (grading, drainage, street, water, and sewer) must be submitted in a clear, neat format, with an uncluttered appearance, which conveys all pertinent information at a one (1) inch equals forty (40) feet (1:500) scale horizontal (one (1) inch equals twenty (20) feet may be required if necessary to meet the appearance of objectives), and one (1) inch equals four (4) feet, (1:50) vertical, or larger. Overall drawing size shall be twenty-four (24) inches by thirty-six (36) inches and shall have a left margin of two (2) inches and a margin of one half (1/2) inch on all other sides. An index map to a set of detailed plans in excess of two (2) sheets shall be presented.

Justification:

The scale conversions are incorrect and redundant.

Section 4. Amend Title 13 Engineering Design Standards, Chapter 13-06: Construction Plans, Division 13-06-002: Plans Required, Section 13-06-002-0004: Drafting Standards, as follows:

E.    Plan originals shall be on a high quality transparent mylar similar or equal to K & E four (4) mil. reverse double mattesubmitted electronically, in PDF format.

F.    Stick-on materials, other than standard Blue Stake stickers, will not be allowed on plan originals.During the Civil Plan Review process, a description of any changes made to each plan sheet since the previous submittal must accompany the resubmittal. The design engineer may choose to cloud the specific changes on the affected plan sheets or provide a list of changes organized by plan sheet and including a description of each substantive change made since the previous submittal. The itemization of the plan changes must include a certification by the design engineer that the list of changes incorporates all changes since the previous submittal. Non-substantive changes such as typo corrections, line weight changes or similar alternations to the plans and which do not affect the functional design need not be included in the list of changes. Where entire plan sheets are replaced or added additional plan review fees must accompany the resubmittal in accordance with the fee schedule adopted at the time of the initial plan submittal.

Justification:

Engineering records are now being electronically submitted, processed, and retained.

Often, design engineers will make changes to a plan set beyond those specific items outlined in the comment response.  This requires plan reviewers to re-check every item on every plan sheet with each subsequent revision resulting in longer plan review timeframes than would otherwise be required.

Section 5. Amend Title 13 Engineering Design Standards, Chapter 13-06: Construction Plans, Division 13-06-002: Plans Required, Section 13-06-002-0005: Cover Sheets, to add the following:

O.    Provide a blank space in the title block, in the same location on each sheet, with an aspect ratio of 2.5:1 for a City approval stamp. It shall be similar in scale to the Engineer’s Stamp.

Justification:

With the use of electronic plan reviews and submittal it has become clear that staff needs to more clearly identify and distinguish plans that have been approved in order to reduce the likelihood of construction occurring based on unapproved plan sets.

Section 6. Amend Title 13 Engineering Design Standards, Chapter 13-06: Construction Plans, Division 13-06-002: Plans Required, Section 13-06-002-0008: As-Built Plans, as follows:

C.    Procedure.

1.    All as-builts shall have an applicant transmittal attached as documentation of who is submitting them. This is necessary in order to process the plans and for contact information when the review is complete. Plans will not be reviewed if this documentation is missing and/or the submittal is deemed incomplete based on the checklist.

2.    All as-built plans submitted for review shall consist of two (2) clean blue or black line paper sets (copied from the original mylars, not a permit set)be submitted electronically, in PDF/A format, containing all the original signatures. One (1) set will be reviewed and returned iIf there are City comments. A, all comments must be addressed and resubmitted. Two (2) revised plan sets will be required with each resubmittal along with the previous redlined review set until final City approval.

3.    Upon City approval, one (1) set of mylars shall be submitted to the City for permanent record. If the project is developed in phases, as-built information/plans willshall be submitted once the work is complete in thatfor each phase.

Justification:

Engineering records are now being electronically submitted, processed, and retained. PDF/A is a standardized version of the Portable Document Format (PDF) specialized for use in the archiving and long-term preservation of electronic documents. PDF/A differs from PDF by prohibiting features unsuitable for long-term archiving, such as font linking (as opposed to font embedding) and encryption.

Section 7. Amend Title 13 Engineering Design Standards, Chapter 13-06: Construction Plans, Division 13-06-002: Plans Required, Section 13-06-002-0009: Final Plan Submittal, as follows:

Upon approval of the construction plans, but prior to the issuance of a permit for construction, one (1)a complete set of “for construction” plans which include the engineer’s seal, date, and signature on each sheet originals (which shall be a four (4) mil reverse double matte mylar of legible quality) and one (1) additional cover sheet shall be submitted to the City for signatures in PDF format. One (1) signed cover sheet The City will apply the approval stamp and the signatures of the City Engineer, Water Services Director and Public Works Director and then will be returned the plans to the consultant design engineer for their records in PDF/A format. The City will retain the complete original set as the official plans for the project. The consultant design engineer will then provide the City with three (3) full-size, legible blueline paper plan sets for issuance of construction Engineering permits. In addition, unless specifically exempted by the City Engineer, the consultant shall provide to the City the approved plans digitally, as required by the City’s "Digital Data Submission Standards" (when developed and adopted).

Justification:

Engineering records are now being electronically submitted, processed, and retained. PDF/A is a standardized version of the Portable Document Format (PDF) specialized for use in the archiving and long-term preservation of electronic documents. PDF/A differs from PDF by prohibiting features unsuitable for long-term archiving, such as font linking (as opposed to font embedding) and encryption.

13-06-003: Grading Plans

Section 8. Amend Title 13 Engineering Design Standards, Chapter 13-06: Construction Plans, Division 13-06-003: Grading Plans, Section 13-06-003-0002: Plan Presentation, as follows:

One (1) mylar (four (4) mil. double matte) of tThe approved grading and drainage plan(s) shall be submitted electronically, in PDF/A format, as public record prior to issuance of the grading permit.

At a minimum, the grading plan shall be prepared in accordance with the City of Flagstaff Stormwater Design Manual and the latest edition of the International Building Code.

Justification:

Engineering records are now being electronically submitted, processed, and retained. PDF/A is a standardized version of the Portable Document Format (PDF) specialized for use in the archiving and long-term preservation of electronic documents. PDF/A differs from PDF by prohibiting features unsuitable for long-term archiving, such as font linking (as opposed to font embedding) and encryption.

13-06-007: General Notes

Section 9. Amend Title 13 Engineering Design Standards, Chapter 13-06: Construction Plans, Division 13-06-007: General Notes, Section 13-06-007-0001: General Notes, to add the following to 13-06-007-0001.A:

21.    All survey monuments within or around the construction area shall be protected in place. Any monuments that are disturbed or displaced by construction shall be reset by the RLS at the contractor’s expense in accordance with City of Flagstaff Engineering Standards Section 13-03-005-0004 and A.R.S. 33-103.

22.    The use of trench plating shall be prohibited from November 1st to April 1st unless specifically allowed by the City Engineer.

Justification:

A note on all construction plans will make contractors aware of the standards for preservation of survey monuments.

Note the revision to MAG Standard Trench Plating detail to accommodate unique weather conditions of Flagstaff as it relates to snow operations.

Section 10. Amend Title 13 Engineering Design Standards, Chapter 13-06: Construction Plans, Division 13-06-007: General Notes, Section 13-06-007-0002: Water and Sewer Notes (Water and Sewer Plans), to add the following:

S.    When any water service or stub such as for a fire line, hydrant line, or main have previously been extended to the frontage of any property to be developed and the approved Civil Plans do not utilize this stub for any purpose, such service or stub shall be abandoned at the main. The valve at the main shall be removed and replaced with a blind flange, repair coupling or other approved method per City of Flagstaff Engineering Standards.

T.    The contractor shall verify that the size of water service and water meter indicated on these plans matches that indicated on the approved building plumbing plan set. In the event there is a discrepancy contact City of Flagstaff Water Services to confirm correct size prior to installation of water service. Where the new service is being installed to a parcel or lot for which no City-approved construction plans exist, consult Engineering Standard Table 13-09-003-04 for the most applicable water service size based on the anticipated use of the property and taking into account those subdivisions where residential fire sprinklers are required.

U.    All new or relocated fire hydrants shall be tested in accordance with AWWA M-17 procedure and observed by a representative of the City Engineer and Water Services Director with the test procedure and results documented on a form prescribed by the City Engineer. All hydrant testing must be scheduled with the Engineering Division. Under no circumstances may an active hydrant be operated by persons other than authorized City of Flagstaff personnel.

Justification:

Note S: Water stub outs are extended to parcels to allow for future development while minimizing disturbance to existing right-of-way.  However when a project design does not utilize those stubs, unnecessary points of potential failure are added to the City water system and need to be abandoned at the nearest active main.

Note T: This will help to ensure proper coordination between building and sewer plans.

Note U: The hydrant testing standard is not currently clarified in the standard. The American Water Works Association Manual AWWA M-17 is widely recognized as the standard test method for fire flow testing.

13-06-008: Construction Traffic Control Plans

Section 11. Amend Title 13 Engineering Design Standards, Chapter 13-06: Construction Plans, Division 13-06-008: Construction Traffic Control Plans, Section 13-06-008-0001: General, as follows: 

A.    A construction traffic control plan is required for any survey, construction, utility, or maintenance activity performed in public rights-of-way or transportation-related easements that impacts the use or function of, or requires the temporary closure of streets, travel lanes, alleys, sidewalks, bikeways or bike lanes, or FUTS trails.

B.    Construction traffic control plans shall be in conformance with the requirements of the Federal Highway Administration’s Manual of Uniform Traffic Control Devices (MUTCD). All traffic control plans shall be approved by the City’s Traffic Engineering Manager City of Flagstaff Traffic Engineering Section prior to issuance of any permits associated with the plans. When a project involves construction that requires a substantial traffic control plan, the plan shall be submitted together with the construction plans to allow for the necessary review time and implementation of phased construction as needed to minimize traffic impacts.

Justification:

Added statement of when a construction traffic control plan is required.

Clarified that Traffic Control Plans are to be approved by the City of Flagstaff Traffic Engineering Section to clean up job title and chain of responsibility.

Section 12. Amend Title 13 Engineering Design Standards, Chapter 13-06: Construction Plans, Division 13-06-008: Construction Traffic Control Plans, Section 13-06-008-0002: Plan Presentation, as follows:

A.    Construction traffic control plans are required for controlling public and construction traffic through work areas and zones as well as for other permitted activities within the public rights-of-way and easements. Traffic control plans may reference particular typical drawings contained in Part VI of the MUTCD for work of a minor nature. Traffic control plans shall be professionally prepared by persons knowledgeable with the fundamental principles of temporary traffic control and the work activities to be performed.

B.    The traffic control plan shall include, but is not limited to, the following:

1.    Scaled drawings conforming to City Standard Specification No. 6-05-010 of the construction zone, detours, construction stages, and affected surrounding areas. The scale of the drawings shall be one (1) inch equals twenty (20) feet (1:200), for construction zones under three hundred (300) feet in length and one (1) inch equals forty (40) feet (1:500) or one (1) inch equals fifty (50) feet (1:500) for construction zones greater than three hundred (300) feet in length. Dimensioned drawings including construction zone, detours, construction staging, and affected surrounding areas.

2.    Project name and address.

3.    City permit number.

43.    Plan preparation date.

54.    Time of day (if applicable) that construction traffic control is to be in place.

65.    Traffic control responsibility (name, address, telephone number and contact person for barricade company).

76.    A listing of all traffic control devices specified for installation.

87.    The size of the work area (all dimensions).

98.    The location of the work area in relation to the cross streets, alleys, or other major reference points (show all distances and dimensions).

109.    Pedestrian and bicyclist accommodation through the construction zone, including temporary realignment or rerouting of How existing pedestrian and bicycle facilities will be temporarily or permanently rerouted through or around the construction zone.

10.    Accessible routes through or around the construction zone that comply with the Americans with Disabilities Act (ADA).

11.    Relocation of transit stops and the continuation of pedestrian access to them. When relocation of a transit stop is required, the traffic control plan shall include a note that reads as follows:

         a.    Permittee shall contact the dispatch office responsible for the transit stop to coordinate relocation a minimum of 3 business days in advance.

12.    Impacts on access to existing parking facilities including, but not limited to, garages, carports, and surface lots.

13.    Provisions for special human resource requirements, such as flaggers (equipment, clothing, and flagging methods are required to conform to the MUTCD in every instance).

14.    Telephone numbers of persons to be contacted in an emergency and for maintenance of traffic control devices.

15.    A construction schedule, as well as a schedule of the times of day when work is permitted or when certain lanes are to remain open. If work extends past approved traffic control plan, a new plan with the updated dates needs to be resubmitted for approval.

16.    A note indicating notification signage to be posted 5 business days prior to work, if required. Variable message boards shall be used for lane reductions on arterial streets, or full closures on arterial, collector, or commercial local streets. Static signage shall be used for full closures on local streets and alleys that are used for access to properties.

17.    A note indicating that the Traffic Control Plan is only approved for implementation on the specific dates and times indicated and when the written approval stamp has applied by the City of Flagstaff Traffic Engineering Section.

Justification:

Removed the requirements for a specific engineering drawing scale.

Removed the requirement to include a City permit number on the traffic control plan

Added that bicycle and pedestrian accommodations need to be made during temporary realignment or rerouting of existing facilities.

Added note that accessible routes need to be included per ADA requirements.

Updated a note to include that the permittee needs to reach out to the transit agency a minimum of 3-days in advance if a transit stop will need to be relocated.

Updated a note to include that a new plan needs to be submitted and approved if work extends past the original dates.

Added a note regarding advanced VMB, when they are required to be posted and which roadways and types of closures it applies to.

Added a note to clarify what criteria must be met for a traffic control plan to be approved for implementation within the City of Flagstaff right-of-way.

13-09-001: Underground Utilities

Section 13. Amend Title 13 Engineering Design Standards, Chapter 13-09: Water, Sewer, and Other Underground Utilities, Division 13-09-001: Underground Utilities, Section 13-09-001-0008: Utility Alignment and Easement Requirements to modify 13-09-001-0008.G, as follows:

G.    Public utility, sewer, and water easements shall be free of all permanent obstructions and shall comply with Division 13-04-001. at all times be accessible to City service vehicles and equipment. No buildings, sport courts, fences, shade structures, or permanent structures of any kind shall be constructed upon, over, or under a water, sewer, or drainage easement. No landscaping shall be placed within an easement which would render the easement inaccessible by equipment. The City of Flagstaff Utilities Division has the right to cause any obstruction to be removed without notice to the property owner and all related costs shall be the property owner’s responsibility.

Justification:

Code is not clear enough on what is allowed to be built in easements. Removing the requirements here and instead referring to Division 13-04-001 will avoid potentially duplicative or conflicting language.

13-09-002: Sewer System Design

Section 14. Amend Title 13 Engineering Design Standards, Chapter 13-09: Water, Sewer, and Other Underground Utilities, Division 13-09-002: Sewer System Design, Section 13-09-002-0005: Velocities of Flow, to modify Table 13-09-002-02 as follows:

Table 13-09-002-02
Pipe Size (inches)	Min. Slope (%) 2 fps **		Max. Slope (%) 10 fps *
	n = 0.010	n = 0.013	n = 0.010	n = 0.013
8	0.20	0.34	4.91	8.29
10	0.15	0.26	3.65	6.16
12	0.11	0.20	2.86	4.83
15	0.085	0. 15	2.12	3.59

Note: *  PVC (n = 0.010) DIP (n= 0.013)

**            Minimum slopes for PVC must also be calculated using a coefficient of roughness of 0.013.

Justification:

ADEQ R18-9-E301 D 2 (e) does not allow for minimum slope calculations to utilize a lower coefficient of roughness than 0.013. COF requirements need to be updated to stay in compliance with ADEQ. ADEQ requires flatter-sloped sewer runs to have quarterly maintenance plan which would become the extra responsibility (burden) of City of Flagstaff Water Services.

Section 15. Amend Title 13 Engineering Design Standards, Chapter 13-09: Water, Sewer, and Other Underground Utilities, Division 13-09-002: Sewer System Design, Section 13-09-002-0007: Design and Spacing of Manholes, as follows:

A.    Manholes are to be installed at the end of each line; at all changes in grade, size, horizontal or vertical alignment, pipe material; at all intersections of mains and service connections greater than six (6) inches in diameter; and at distances not greater than four hundred (400) feet for sewers twelve (12) inches or less, and five hundred (500) feet for sewers greater than twelve (12) inches.

Table 13-09-02-004 Minimum Manhole Diameter
PIPE SIZE (INCHES)	MANHOLE DEPTH (FT)	MANHOLE DIAMETER (INCHES)	FRAME AND COVER DIAMETER (INCHES)
Less than 12"	12 and less	48	24
Greater than 12"	Greater than 12	60	30
15" and larger	Any	60	30
Drop Manholes	Any	60	30

C.    A drop manhole is to be used when a sewer enters a manhole two and one-half (2.5) feet or more above the manhole invert in accordance with MAG Detail No. 426.

1.    If there is less than two and one-half (2.5) feet of fall, redesign of sewer grades is required to result in a maximum of one-half (0.5) foot above the flow line of the outlet.

2.    Sewer grades shall be normally designed to provide one-tenth (0.1) foot fall from the flowline inlet to the flowline outlet within the manhole.

3.    When a sewer main joins a ten (10) inch or greater main, the top of each pipe shall match at their intersection of the manhole.

a.    The maximum horizontal deflection angle (inlet to outlet) for an eight (8) inch main shall be ninety (90) degrees.

b.    For mains ten (10) inches and larger the maximum defection angle shall be sixty (60) degrees.

c.    The minimum flow line radius shall be two (2) feet.

D.    Concrete caps on manholes located outside roadways or parking lots shall have a continuous No. 3 rebar centered in the cap.

E.    One (1) adjustment ring or one (1) row of bricks is required on all manholes. The ring and cover shall not be set directly on the cone.

F.    Manhole covers must have a pickhole and watertight manhole covers must have a concealed type pickhole for removal of the cover. Bolts on watertight manhole lids shall be stainless steel.

G.    Where corrosive conditions due to septicity or other causes are anticipated, consideration shall be given to providing corrosion protection on the interior of the manholes.

H.    Manholes shall be pre-cast concrete or poured-in-place concrete type. Manhole lift holes and grade adjustment rings shall be sealed with non-shrinking mortar.

1.    Inlet and outlet pipes shall be joined to the manhole with a gasketed, flexible water-tight connection or any water-tight connection arrangement that allows differential settlement of the pipe and manhole wall to occur.

I.    Watertight manhole covers shall be used whenever the manhole is located in a floodplain, wash, or other areas known to be subject to stormwater runoff.

J.    Locked manhole covers may be required in isolated easement locations or where vandalism is anticipated.

K.    When connecting to an existing manhole, coring will not be accepted. The connection must be made with a new cast in place manhole.

L.    Manholes should be located outside of sidewalks, bikeways, bike lanes, and FUTS trails when feasible.

Justification:

We typically allow for a change in pipe material without requiring a manhole when extra protection is required per MAG 404-2.

Resurfacing the existing manhole sacrifices the integrity of the manhole base.

Code does not currently disallow manholes being located in sidewalks, bikeways, bike lanes, and FUTS trails.

Section 16. Amend Title 13 Engineering Design Standards, Chapter 13-09: Water, Sewer, and Other Underground Utilities, Division 13-09-002: Sewer System Design, Section 13-09-002-0010: Sewer Services, to modify 13-09-002-0010.A as follows:

A.    Sewer services shall be installed perpendicular (not parallel) to the right-of-way or easement, within the right-of-way or easement, and shall not be installed across another’s private property parcel or lot except where service is perpendicular to, and entirely within a public utility or sewer easement. Private easements across separate parcels will not satisfy the requirements of this section. Sewer services are prohibited on sewer transmission mains that are eighteen (18) inches or larger.

Justification:

Current language has been interpreted by some applicants to indicate that a sewer service may pass under an adjacent parcel if the same party owns both parcels. This creates problems for access and repair, particularly if one parcel is later sold.

13-09-003: Water System Design

Section 17. Amend Title 13 Engineering Design Standards, Chapter 13-09: Water, Sewer, and Other Underground Utilities, Division 13-09-003: Water System Design, Section 13-09-003-0005: Valve Locations, to modify 13-09-003-0005.B as follows:

B.    Valves shall be generally located as follows, unless otherwise approved by the Utilities Division:

1.     At intervals to isolate no more than two (2) fire hydrants at any time.

2.    At minimum intervals of five hundred (500) feet in commercially zoned areas and residential off-site water mains.

3.     In residential areas to isolate a maximum of thirty (30) services (approximately six hundred (600) feet).

4.     At minimum intervals of eight hundred (800) feet for transmission lines.

5.    Valves shall not be located in street gutters, valley gutters, concrete aprons, or in driveways.

6.     Valves should be located outside of sidewalks, bikeways, bike lanes, and FUTS trails when feasible.

7.    Three (3) valves are required on a four (4) way cross, two (2) valves minimum are required on all three (3) way tee fittings.

Justification:

Added statement that water valves should be located outside of sidewalks, bikeways, bike lanes, and FUTS trails, when feasible.

Section 18. Amend Title 13 Engineering Design Standards, Chapter 13-09: Water, Sewer, and Other Underground Utilities, Division 13-09-003: Water System Design, Section 13-09-003-0007: Water Services, to modify 13-09-003-0007.F as follows:

F.    Water services, meter, and box shall be installed perpendicular (not parallel) to the main line, within the right-of-way or easement, and. Water services shall not be installed across another’s private property parcel or lot except where service is perpendicular to, and entirely within a public utility or water easement containing a public water main on the affected lot. Water service easements across separate parcels will not satisfy the requirements of this section. Water service lines between a water main and water meter shall be installed perpendicular to the water main unless otherwise approved by the City Engineer. Water meters shall be located at the frontage of the lot being served.

Justification:

Current language has been interpreted by some applicants to indicate that a water service may pass under an adjacent parcel if the same party owns both parcels. This creates problems for access and repair, particularly if one parcel is later sold. The location requirement for water meters is not clearly spelled out in code.

13-09-006: Sewer and Water Line Materials

Section 19. Amend Title 13 Engineering Design Standards, Chapter 13-09: Water, Sewer, and Other Underground Utilities, Division 13-09-006: Sewer and Water Line Materials, Section 13-09-006-0006.2: Fire Hydrant Specifications, to modify 13-09-006-0006.2.R as follows:

R.    A class "A" concrete pad four (4) to six (6) inches thick and three (3) feet by three (3) feet square shall be placed around a fire hydrant barrel a minimum of threetwo (32) inches and a maximum of eight (8) inches below the bottom of a traffic flange; six (6) inches maximum.

Justification:

The pipe for connecting the hydrant comes in lengths that are multiples of six inches. Increasing the allowable range from four to six inches will make it easier for contractors to get a configuration that meets the standard.

Section 20. Amend Title 13 Engineering Design Standards, Chapter 13-09: Water, Sewer, and Other Underground Utilities, Division 13-09-006: Sewer and Water Line Materials, Section 13-09-006-0006.3.A(5):

c.    When ten (10) foot spacing from the edge of the driveway is not practical, the design shall maximize available space behind the sidewalk.

Justification:

Many residential neighborhoods cannot accommodate the maximum hydrant spacing requirement and maintain the 10-ft minimum separation from the driveway. This is also a growing issue with new developments where there are wide, shared driveways and narrow lots.

13-10-002: Street Design

Section 21. Amend Title 13 Engineering Design Standards, Chapter 13-10: Streets, Division 13-10-002: Street Design, Section 13-10-002-0001: Street Design, as follows:

Note: Tables 13-10-011-01 and 13-10-011-02 are proposed to be moved here from Section 13-10-011-0001 with minor changes. For this revision only, standard text denotes provisions that have not changed or that have been moved here from 13-10-011-01 without change, bold strikethrough denotes provisions that are being deleted, and bold text denotes new provisions that are not in previously approved code.

Street design shall:

A.    Provide for appropriate continuation of existing and proposed arterial and collector streets and bikeways in accordance with the most recently adopted version of the Regional Plan and Division 13-10-014.

B.    Provide sufficient rights-of-way for local service or a frontage street along major highways, or other treatment by separation to protect residential properties along arterial and collector streets.

C.    Correlate with the drainage facilities when streets are used for on-site local drainage.

D.    Be designed so that through traffic in residential districts is carried on arterial and collector streets. Residential subdivisions shall be designed so that the local streets provide vehicular, bicycle, and pedestrian access to the residences and services of the homes fronting the streets. Table 13-10-011002-01 identifies the application of the different street cross sections, which are based on the total traffic volumes of the street.

1.    In order to provide neighborhoods that are safe, functional, and express an atmosphere of community, subdivisions shall should be designed so that the residential local streets carry volumes no greater than one thousand five hundred (1,000500) ADT. When the traffic volumes on a given street exceed one thousand five hundred (1,000500) ADT, it shall should only provide access to a local street and not to residential properties. In those instances, the typical street section used shall be a minor collector as follows: The section will exclude the center left turn lane (left turn lanes will be required as needed where the minor collector intersects another collector or arterial street).

Table 13-10-011002-01 Functional Classification/Design Criteria
URBAN
Functional Classification(*)	Major Arterial	Minor Arterial	Major Collector	Minor Collector	Commercial Local	Residential Local "Wide"	Residential Local
Max. Through Lanes	4	4	4	2	2	2	2
Maximum Average Daily Traffic						1,000	500
On Street Parking	Not allowed	Not allowed	Not allowed	Not allowed	Not allowed	Not striped	Not striped
Bicycle Provision	4.5'	4.5'	4.5'	4.5'	In travel lane	In travel lane	In travel lane
Total A.C. Width	68'	68'	**68'/64'	42'	24'	33'	29'
Width (B.C. to B.C.)	72'	72'	**72'/68'	46'	28'	37'	33'
Minimum R.O.W. (See Note No. 2)	98'	98'	**96'/92'	70'	52'	61'	57'
Through Lane Width	12'	12'	12'>/=40 mph 11'<40 mph	11'	12'	NA	NA
Auxiliary Lane Widths	11'	11'	11'	11'	NA	NA	NA
Edge Treatments	Vertical C/G	Vert. C/G	Vert. C/G	Vert. C/G	Vert. C/G	Vert. C/G	Vert. C/G ***
Min. Sidewalks (See Note No. 3)	6'	6'	5'	5'	5'	5'	5'
Min. Parkway (See Note No. 8)	5'	5'	5'	5'	5'	5'	5'
Parking Lane	Not allowed	Not allowed	Not allowed	Not allowed	Not allowed	Not striped	Not striped
Minimum Median Width (See Note No. 7)	15'	15'	15'	NA	NA	NA	NA
Max. A.C. Width @ Signal w/o Median	68'	68'	68'	68'	NA	NA	NA
Max. A.C. Width at Nonsignalized Inters. w/o Median	48'	48'	48'	48'	NA	NA	NA
Corner Cut-Off (See Note No. 4)	25'	25'	20'	15'	15'	15'	15'
Curb Ret. Radius	30'	30'	25' **	20' **	20'	15'	15'
Design Speed	45 MPH	40 MPH	35–40 MPH	30 MPH	25 MPH	20 MPH	20 MPH
Superelevation (See Note No. 5)	4% Max.	4% Max.	4% Max.	None	None	None	None
Min. Curve Radius (See Note No. 5)	900'	667'	667' (40 mph) 454' (35 mph)	300'	181'	100'	100'
Maximum Grade	6%	6%	6%/7%	8%	10%	10%	10%
Property Access (See Note No. 6)	Major D/W Only	Major D/W Only	Major or Combined D/W Only	Individual D/W Head Out	Individual D/W Head Out	Individual D/W Back Out	Individual D/W Back Out

*    Functional classifications are further defined in Division 13-10-014.

**    1.    For travel lanes adjacent to a raised median, increase travel lane width by one (1) foot.

    2.    For all truck routes, there must be a minimum through lane width of twelve (12) feet and a thirty (30) foot curb return radius at intersections.

***    Rolled curb ismay be permitted on local streets in new single-family and townhome and planned options where lot widths are less than or equal to forty (40) feet. This is limited to those streets within the development that front the houses.subdivisions, subject to the following minimum criteria:

1.    Where 95% of the lots within the subdivision have a width of less than or equal to fifty (50) feet,

2.    Vertical curb is not otherwise required for drainage,

3.    A minimum 5’ parkway separates the back of curb from the sidewalk except at Cul-de-sacs where roll curb may be placed adjacent to sidewalks,

4.    Roll curb is constructed in accordance with the current MAG standard details and subject to any City of Flagstaff Revisions,

5.    Vertical curb shall be used through all curb returns and shall include minimum 5’ curb transitions from point of curve to point of tangency and per MAG Standard Detail 221,

6.    ADA-compliant curb ramps are provided at all intersections and where mid-block crossings are designated,

7.    Unless otherwise stipulated during Preliminary Plat Approval, the Final Plat shall include the following note: “No more than one 20-foot wide driveway access point may be placed on each lot.”

Table 13-10-011002-01 (Continued) Functional Classification/Design Criteria
URBAN
COMMERCIAL CENTER STREETS
Functional Classification (*)	Major Arterial	Minor Arterial	Major Collector	Minor Collector	Local
Max. Through Lanes	4	4	4	2	2
On Street Parking	6'	6'	6'	6'	6'
Bicycle Provision	5'	5'	5'	5'	In travel lane
Total A.C. Width	81'	81'	81'/77'	55'	36'
Width (B.C. to B.C.)	85'	85'	85'/81'	59'	40'
Minimum R.O.W. (See Note No. 2)	117'	113'	113'/109'	87'	68'
Through Lane Width (**)	12'	12'	12'>/=40mph 11'<40mph	11'	12'
Auxiliary Lane Widths	11'	11'	11'	11'	11'
Edge Treatment	Vert. C/G	Vert. C/G	Vert. C/G	Vert. C/G	Vert. C/G
Min. Sidewalks	10'	10'	10'	10'	10'
Furnishing Strip	5'	3'	3'	3'	3'
Offset	1'	1'	1'	1'	1'
Parking Lane	6'	6'	6'	6'	6'
Minimum Median Width (See Note No. 7)	15'=11' lane + 4' median	15'	15'	NA	NA
Max. Number of Lanes at a Signal w/o Median	6	6	6	6	NA
Max. Number of Lanes at a Nonsignalized Intersection w/o Median	4	4	4	4	NA
Corner Cut-Off (See Note No. 4)	25'	25'	25'	15'	15'
Curb Ret. Radius	30'	30'	20' **	20' **	25'
Design Speed	45 MPH	40 MPH	35–40 MPH	30 MPH	25 MPH
Superelevation (See Note No. 5)	4% Max.	4% Max.	4% Max.	None	None
Min. Curve Radius (See Note No. 5)	900'	667'	667' (40 mph) 454' (35 mph)	300'	181'
Maximum Grade	6%	6%	6%/7%	8%	10%
Property Access	Major D/W Only	Major D/W Only	Major or Combined D/W Only	Individual D/W Head Out	Individual D/W Back Out

*    Functional classifications are further defined in Division 13-10-014.

**    1.    For travel lanes adjacent to a raised median, increase travel lane width by one (1) foot.

    2.    For all truck routes, there must be a minimum through lane width of twelve (12) feet and a thirty (30) foot curb return radius at intersections.

Table 13-10-011002-01 (Continued) Functional Classification/Design Criteria
RURAL
Functional Classification (*)	Major Arterial (See Note No. 3)	Minor Arterial (See Note No. 3)	Major Collector (See Note No. 1)	Minor Collector (See Note No. 1)	Local	Local Narrow
Max. Through Lanes	2	2	2	2	2	2
On Street Parking	Not allowed	Not allowed	Not allowed	Not allowed	Not striped	Not striped
Bicycle Provision	4'	4'	4'	4'	In travel lane	In travel lane
Total A.C. Width	32'	32'	32'	30'	26'	20'
Minimum R.O.W. (See Note No. 2)	60'	60'	60'	60'	50'	44'
Through Lane Width (**)	12'	12'	12'	12'	13'	10'
Edge Treatment	6 Foot Compacted Shoulders and Drainage Swales/Curb and Gutter Is Optional (See Note No. 9)
Sidewalks	No Sidewalks or Parkway Section
Parking Lane	Not allowed	Not allowed	Not allowed	Not allowed	N/A	N/A
Corner Cut-Off	30'	30'	20'	20'	20'	20'
Fillet Radius	30'	30'	20' **	20' **	20'	20'
Design Speed	45 MPH	40 MPH	35-40 MPH	30 MPH	20 MPH	20 MPH
Superelevation (See Note No. 5)	4% Max.	4% Max.	4% Max.	None	None	None
Min. Curve Radius (See Note No. 5)	900'	667'	667' (40 mph) 454' (35 mph)	300'	100'	100'
Maximum Grade	6%	6%	7%	8%	10%	10%
Property Access	Major D/W Only	Major or Combined D/W Only	Major or Combined D/W	Individual D/W Head Out	Individual Back Out	Individual Back Out
Min. D/W to Intersection	(See Note No. 10)	(See Note No. 10)	(See Note No. 10)	(See Note No. 10)	10'	10'

*    Functional classifications are further defined in Division 13-10-014.

**    1.    For travel lanes adjacent to a raised median, increase travel lane width by one (1) foot.

    2.    For all truck routes, there must be a minimum through lane width of twelve (12) feet and a thirty (30) foot curb return radius at intersections.

NOTES:

1.    Rural residential local streets are for local access in lower density residential areas only. They provide a less intrusive design option for streets, which will experience low traffic volumes and no on-street parking. Critical to their successful operation is a site design that eliminates virtually all demand for on-street parking by providing large setbacks, long driveways, and many convenient on-site parking spaces for each dwelling.

The following minimum development criteria must be met for the rural residential local streets:

Cluster and Single-Family Detached Development – The rural residential local street shall be used where the minimum lot size is twenty-five thousand (25,000) square feet. The rural residential local "narrow" street shall be used where the minimum lot size is one (1) acre.

2.    Additional right-of-way and/or easements may be required to accommodate turn lanes, traffic signals at intersections, drainage features, et cetera.

3.    Sidewalks wider than five (5) feet may be required if high volumes of pedestrian traffic are expected, or in order to match existing adjacent sidewalks and master development plans.

4.    The corner cut-off is normally a straight diagonal right-of-way line. A circular arc of this radius may be used if approved by the City Engineer.

At the intersection of two (2) streets of different classifications, the corner cut-off dimension and the curb return or fillet radius of the higher classification street shall be used.

5.    For arterial and major collector streets, the relationship between super-elevation rate, runoff, and curve radius shall be determined from AASHTO tables for e-max equals four percent (4.0%). For local streets, the minimum delta angle (D) must be greater than thirty (30) degrees. Minimum curve radii in the table are based on no super-elevation.

6.    Pavement edge tapers shall be designed in accordance with City of Flagstaff Detail No. 10-10-031.

7.    Medians shall be required on all arterials and major collectors and as outlined in Table 13-10-011-01, or as required by the City Engineer.

8.    Where new sidewalk is required in an existing development, the City Engineer may waive the requirement of a parkway if it is not practical to construct.

9.    Where two (2) local residential "narrow" streets do not intersect at a right angle, the radius of curb returns on the acute angles shall be twenty (20) feet.

10.    See Section 13-10-006-0001 for location of driveways adjacent to intersections.

11.    For design criteria not addressed in this table, refer to AASHTO.

E.    Require that new designs incorporate traffic calming techniques into all new residential streets. The goal is to reduce residential traffic speeds to within the design speed limits, while maintaining safe and reasonable access for all intended normal traffic. In order to achieve this objective, the maximum length of a roadway section between speed control points shall be six hundred sixty (660) feet. A speed control point is defined as any one (1) of the following:

1.    Any design condition that requires a complete stop such as the intersection of a local residential street with a collector or arterial street, or a "T" intersection between local streets. (Note: Stop sign control at the intersection between local streets does not qualify.)

2.    A horizontal curve that does not exceed a radius of three hundred (300) feet and a corresponding delta of thirty (30) degrees minimum.

In the event that there are circumstances where it is not practical to achieve traffic calming measures with design features as stated above, Table 13-10-011002-02 is intended to provide the design engineer with a list of alternative traffic calming design features (listed in order of preference).

See Design Criteria, Table 13-10-011-01, for the design overview.

Table 13-10-011002-02 – New Design and Retrofit of Existing Streets Traffic Calming Design Features for Local Residential Streets
Design Option	Description	Diagram	Advantages	Disadvantages
Neighborhood Traffic Circle	Raised circular islands placed in intersections, around which traffic circulates. Typically, min. 14' diameter and includes 2-foot wide mountable truck apron and landscaping		a. Effective moderating speed b. Improves safety c. Located at intersections, the ability to calm two streets d. Fixes grid that is adjacent e. Aesthetic landscape opportunity	a. Difficult for large trucks to circumnavigate b. Designed such that the travel lane does not encroach upon crosswalks c. May eliminate on-street parking d. Maintenance e. Larger trucks may have to violate lane to navigate
Roundabout a. Local to collector b. Local to arterial c. Permitted under special circumstances	Larger than traffic circles and typically extends a minimum of 28' from center with 2' truck apron. The inscribed diameter should be 88' and 200'. Circulating roadway has a width of 14' to 19'		a. Moderates traffic speeds on arterials b. Enhanced safety as compared to signalization c. Less operating expenses as compared to signalization	a. May be difficult to navigate with large trucks b. Designed such that the travel lanes do not encroach into crosswalks c. Eliminates some on-street parking
Curb Extension a. Swells b. Elephant ears c. Located at intersections only	Comprises an angled narrowing of the roadway and widening of the sidewalk		a. Improves pedestrian circulation and space b. Through and left-turn movements are easily negotiable by large vehicles c. Creates protected on-street parking bays d. Reduces speeds, especially for right-turning vehicles	a. Effectiveness is limited by the absence of vertical or horizontal deflection b. May require the elimination of some on-street parking near the intersection c. May require slow right-turning emergency vehicles d. May require bicyclists to briefly merge with vehicular traffic e. May create pedestrian conflict
Center Island Narrowing	A raised island located along the centerline of a street that narrows the travel lanes at that location. A min. of 6' x 20' and landscaped with pedestrian cut-through		a. Increases pedestrian safety b. Reduces traffic volume	a. Speed reduction effect is limited by absence of any vertical and horizontal deflection b. Eliminates some on-street parking c. 300' to 500' spacing between center islands for smooth speeds
Realigned Intersection	Changes in alignment that convert T-intersections with straight approaches into curving streets that meet at right-angles		a. Effective at reducing speeds and improving safety at T-intersections that have been ignored by motorists b. Eliminates unnecessary pavement	a. Curb realignment could be costly b. May require additional right-of-way
Choker	Midblock curb extensions that narrow the street by expanding the sidewalk or adding a planting strip and often are installed at midblock crossings		a. Easily negotiated by large vehicles b. Reduces speed and volume	a. Effect upon speed is limited by the presence of vertical and horizontal deflection b. Bicycles briefly merge with traffic c. Eliminates some on-street parking
Chicane	Literal shifts that alternate on both sides of the street creating a S-shaped path of travel		a. Reduces speed through horizontal deflection b. Larger vehicles can easily negotiate	a. Designed to prevent drivers from varying from lane b. Curb alignment and landscaping could be costly c. Drainage a consideration d. May eliminate some on-street parking e. Snow plowing may be difficult to maneuver
Textured Pavement	A surface material on the roadway (such as stamped asphalt or concrete) which is installed to produce small, constant changes in vertical alignment		a. Reduces speed over an extended length b. Located at intersection, can reduce speeds on two streets	a. Generally expensive due to material b. Cross-walk application may cause difficulties for those with disabilities and cyclists to traverse c. Less effective
Truncated Diagonal Diverter	A diagonal diverter with one end open to allow for additional turning movements		a. Discourages commuter traffic by forcing turns	a. Reduces local access b. Displaces traffic to other streets c. Costs
One-Way, Two-Way	Curb bulge or center island narrows 2-lane, forcing traffic for each direction to take turns		a. Limited, rarely used	a. Limited, rarely used
Median Barriers (Applied at intersections in special circumstances)	Intersection island blocking movement of a through street		a. Improves safety at an intersection of a local street and a major street by prohibiting dangerous turning movements b. Reduces traffic volumes on a cut-through route that intersects a major street	a. Requires available street width on the major street b. Limits turns to and from the side street for local residents and emergency services c. Reduces access to driveways on major arterials
Pavement Markings Note: Applies only to retrofit of existing streets	Painted striping or channelization to guide traffic		a. Modestly affects speed	a. Extreme unacceptable aesthetic
Full Closures Note: Applies only to retrofit of existing streets	Full closures divert traffic off the street, creating pedestrian and bicycle friendly areas		a. Maintains pedestrian and bicycle access b. Effective in reducing traffic volume	a. Causes circuitous routes for local residents and emergency service vehicles b. May be expensive c. May limit access to businesses d. May increase volumes in remaining routes
Half Closures Note: Applies only to retrofit of existing streets	Similar to full closures, are barricades located in the street and constructed of landscaped walls, gates, side-bollards, or other obstructions		a. Maintains pedestrian and bicycle access b. Effective in reducing traffic volume	a. Causes circuitous routes for local residents and emergency service vehicles b. May limit access to businesses c. Depending on the design, drivers may be able to circumvent the barrier
Diagonal Diverters Note: Applies only to retrofit of existing streets	A barrier placed diagonally across an intersection disconnecting the legs of the intersection		a. Does not require a closure per se, only a redirection of existing streets b. Able to maintain full pedestrian and bicycle access c. Reduces traffic volumes	a. Cause circuitous routes for local residents and emergency service vehicles b. May be expensive c. May require reconstruction of corner curbs

F.    LID Integrated Management Practices (IMPs) as detailed in the City’s LID Guidance Manual as adopted as part of the City of Flagstaff Stormwater Management Design Manual may be allowed in the right-of-way on a case-by-case basis as approved by the City Engineer and Public Works section head.

Only stormwater generated in the public right-of-way will be allowed to be associated with an IMP. No stormwater generated on private property will be allowed to be associated with an IMP in the right-of-way.

LID IMPs, if allowed in the public right-of-way, shall be considered private drainage infrastructure. Ownership and maintenance responsibilities for LID IMPs shall be as described in the amendments to the Floodplain Management Regulations.

Justification:

The tables were located in the section of code for resource and slope design criteria but are not related resource or slope protection. The street design section of code is a more logical location. Moving them there will make them easier to locate when browsing.

Due to the tight spacing of driveways and lack of parkway, meeting sidewalk ADA cross-slope requirements is impractical at cul-de-sacs without either parkway or the use of roll curb. Many newer subdivisions are incorporating higher densities and smaller lots, resulting in the need for a high percentage of vertical curb to be cut for driveway entrances. Roll curb would, in many cases, result in lower costs and improved carbon neutrality.

13-10-006: Intersection Design

Section 22. Amend Title 13 Engineering Design Standards, Chapter 13-10: Streets, Division 13-10-006: Intersection Design, Section 13-10-006-0001: Intersection Design, as follows:

A.    Intersections concerned with an arterial or collector shall be joined to provide a minimum length of tangent (at right angles to the adjoining street and measured from the curb return of the adjoining street) as follows: arterial – one hundred (100) feet, major collector – seventy-five (75) feet, minor collector – fifty (50) feet, and local – fifty (50) feet. The only exception to this is when a local street intersects a minor collector.

B.    Intersections not involving arterial and major collector streets shall have a minimum intersecting angle of seventy-five (75) degrees. Where two (2) residential local streets intersect, the minimum angle shall be sixty (60) degrees.

C.    Through vehicle and bicycle lanes shall align through intersections involving Arterials and Major Collectors. Intersections involving Minor Collectors and Locals should align but may have offsets up to four (4) feet across the width of the intersection.

CD.    Curb return radii shall be as shown in Table 13-10-011002-01.

DE.    Distances between centerlines of adjacent intersections shall be a minimum of one hundred thirty-five (135) feet, regardless of the direction of the intersecting streets.

EF.    Traffic control device locations shall be shown on the construction plans. Materials and workmanship shall be approved by the City Engineer and shall be in conformance with the guidelines of the Federal Highway Administration and the Manual on Uniform Traffic Control Devices (M.U.T.C.D.) current edition of the MUTCD. All traffic controls shall be installed by the developer prior to occupancy.

FG.    Monuments shall be placed at the intersection of right-of-way centerlines. Refer to Section 13-03-002-0007 for survey monuments.

GH.    Additional right-of-way will be required at intersections where turn lanes are required.

HI.    Intersection grades shall conform to City of Flagstaff Standard Engineering Details except the maximum grade on all approaches to a signalized intersection or an intersection, which is likely to be signalized in the future, shall be plus or minus three two percent (32%) for a distance of three hundred (300) feet from the center of the intersection. Intersections that are roundabout controlled shall be plus or minus four percent (4%) for a distance of two hundred (200) feet measured along the approach to the entering leg crosswalk. Intersections shall maintain a maximum 2% cross slope in all direction inclusive of the crosswalks.

IJ.    The minimum spacing of driveways to signalized and unsignalized intersections shall be according to Table 13-10-006-01. The minimum spacing shall be greater as needed to avoid the functional area of an intersection or the influence area of another driveway.

The functional area extends both upstream and downstream from the physical intersection area and includes the longitudinal limits of auxiliary lanes. The influence area associated with a driveway includes (1) the impact length (the distance back from a driveway that cars begin to be affected), (2) the perception-reaction distance, and (3) the car length. Additionally, the impact length represents the distance upstream when the brake lights of through vehicles are activated or there is a lane change due to a turning vehicle. Limited access driveways (i.e., right-in and right-out only) and driveways with right turn deceleration lanes may allow a shorter minimum spacing.

For signalized and unsignalized controlled intersections the mMinimum spacing shall be measured from curb return of the intersecting street to the pavement edge of the driveway. For roundabout controlled intersections minimum spacing shall be measured from the pavement edge of the driveway to the crosswalk.

Table 13-10-006-01
Minimum Spacing of Driveways to Intersections
SIGNALIZED
Posted Speed (mph)	Minimum Spacing to Intersection (ft)
< or =30	230
35	275
40	320
45	365
UNSIGNALIZED
30	115
35	135
40	155
45	180
ROUNDABOUT
≤ 30	50
35	50
40	75
45	75

Justification:

Added requirements for lane alignment through intersections.

Changed the approach intersection grade for signalized, or likely to become signalized, intersections from 2% to 3%. 

Added the approach intersection grade for a roundabout to be 4% for 200-ft.

Added that an intersection shall maintain a maximum 2% cross slope. 

Added a table for minimum spacing of driveways to a roundabout controlled intersection.