13-16-002

Division 13-16-002
Signal Design Elements

Sections:

13-16-002-0002 Intersection Design Requirements

13-16-002-0001 Plan Set

A. For clarity of presentation and understanding, the plan set for a new traffic signal installation should contain the following sheets: the cover sheet, signal plan sheet, pole schedule sheet, conductor schedule sheet, civil plan sheet, signing and pavement markings sheets, and a detail sheet. The contents of the plan set may vary from this for projects involving modification of existing signals or where the new signal is included as a part of a larger construction project.

1. The cover sheet shall meet the requirements of Section 13-06-002-005, Cover Sheets.

2. The traffic signal plan sheet (one (1) inch equals twenty (20) feet) shall show the signal-related details, such as: cabinets, poles, conduits, pull boxes, phasing indications, detection, and pavement markings. It should also show utility locations and existing, current, and future roadway construction. Minor civil construction improvements may be included on this sheet. The plan sheet shall include general notes and notes for the signal construction.

3. The pole and conductor schedule sheets shall each include a reduced scale intersection plan view to serve as an index to the schedules on these sheets. The reduced scale plan shall include curb lines, pavement markings, cabinets, poles, and conduits with their designations, and signal heads with their phasing.

4. The pole schedule sheet shall also include separate phasing diagrams for the new signal, future phasing, if any, and preemption and other special programs. It shall also include the timing to be programmed for initial operation at start-up.

5. The conductor schedule sheet shall include a table showing individual conduits and sizes; the cables, conductors or pull wires to be placed within each of them; notes relating to cable, conductor, and electrical service; and ADOT standard schedules for IMSA multi-conductor cables.

6. The civil plan sheet(s) shall be provided to show, separate from traffic signal installation plan, the design of other elements included in the project. These elements include such work as replacement of curb or sidewalk, additional pavement for turn lane storage, drainage structures, relocations of existing improvements and utilities, and new sidewalk ramps.

7. The signing and pavement markings sheet shall detail type, size, and location of all permanent and temporary signs and pavement markings and any additional information required to manage traffic safely at each phase of the construction.

8. The detail sheet shall be used for any design and construction details that are unique to the particular project or are not included in the references standards and other documents.

B. All drawings shall distinguish clearly between existing features, proposed construction with this project, and future construction or construction by others. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-16-002-0002 Intersection Design Requirements

Refer to Division 13-10-006, Intersection Design, for geometric standards.

A. Curb returns shall be constructed or reconstructed to provide dual ramps and minimum ten (10) foot spacing between signal poles in accordance with Standard Drawings 10-10-034 through 10-10-039.

B. Signal equipment shall be located to accommodate anticipated future widening or additional approaches in order to minimize future modifications to the signal.

C. Cabinets shall be located out of clear view zones for traffic at the intersection and at adjacent driveways.

1. Consideration shall be given to locating cabinets and other signal equipment so as not to block driver view of adjacent, preexisting commercial advertising signs or businesses.

D. The foundation for the traffic signal cabinet shall be oriented such that the door of the cabinet opens away from intersection. A concrete technician’s maintenance pad, four (4) inches thick, four (4) feet wide, and the length of the cabinet foundation shall be placed on the door side of the foundation. The elevation of the top of the pad shall be two (2) inches above adjacent curb for positive drainage. The cabinet foundation shall be four (4) inches higher than the technician’s maintenance pad.

E. Signals shall be designed with an "8-pole" design; that is, two (2) signal poles on each corner of the intersecting streets.

1. The minimum distance between the two (2) poles shall be ten (10) feet in accordance with ADA requirements for separation of pedestrian detection.

F. Street lighting at the intersection shall be accommodated on combination signal poles rather than by the installation of separate streetlight poles.

1. The number and location of luminaires varies with the size of the intersection, in accordance with Section 13-12-003-0002.

2. Luminaire shall be installed on twenty (20) foot mast arms unless otherwise specified.

G. Poles shall be located so as not to impede sidewalk or ramp traffic. All poles having a pedestrian push button station shall be located adjacent to a sidewalk or sidewalk ramp, or shall have an access pad installed to meet the requirements of the Americans with Disabilities Act. Reach distance to push button stations shall not exceed ten (10) inches.

H. Each pole foundation shall be provided with a one-half (1/2) inch PVC drain to allow water to drain from the pole adjusting-nut sump.

I. Overhead left turn signal heads shall be ADOT Type G, unless protected only phasing, when Type R shall be utilized.

J. Side of pole mounted left or right turn signal heads shall be ADOT Type G, each installed on an individual Type V mount.

K. Pole top mounted right or left turn signal heads shall be ADOT Type G. These may be mounted on a combination mount with one (1) other signal head.

L. Mast arm mounted signal heads shall be centered vertically over traffic lanes.

M. Seven (7) conductor IMSA cable shall be run to each outboard signal head.

N. The intersection will be "boxed" with two (2) three (3) inch diameter conduits.

1. One (1) conduit shall contain higher voltage signal and lighting conductors.

2. The second conduit shall contain lower voltage detection, preemption and communications conductors.

O. All splicing will occur in the No. 7 pull box.

P. When the intersection lies along the path of a future fiber optic interconnect route, two (2) additional three (3) inch conduits, each with a No. 8 green THW pull wire, shall be installed along that route throughout the project limits. Interconnect pull boxes shall not be placed in sidewalk areas when possible, but behind sidewalks or in greenways to minimize tripping hazards.

1. Interconnect pull boxes shall be installed no more than six hundred sixty (660) feet apart and shall be polymer fiberglass ADOT Type 7 traffic signal boxes with a twelve (12) inch extension. The lids shall have a legend with one (1) inch minimum letters that read "Interconnect."

2. Dedicated interconnected pull boxes shall be installed adjacent to the traffic signal pull boxes at intersections.

3. A three (3) inch conduit shall be installed to the traffic signal cabinet from the closest interconnect pull box.

Q. All trenches in existing pavement shall be slurry backfilled and T-topped.

R. A minimum of one (1) No. 7 pull box, with extension, shall be installed on each corner of the intersection, and at each fiberoptic interconnect location.

S. Controller operation shall be NEMA dual ring. Phase 2 shall be used for the main street through movement, either the eastbound or northbound direction.

T. Flashing mode shall be all red. (Ord. 2017-22, Rep&ReEn, 07/05/2017)