Chapter 5: Traffic Signal Projects

Section 1: Overview

Introduction

This chapter explains traffic signal project funding and programming, methods of construction, submission requirements, and project construction. The submissions consist of information gathered during the traffic study and include various forms, graphs, sketches, plans, and other justification data.

Authorization Request Form

Districts use the Traffic Signals Authorization Request Form (See Appendix A) to recommend the type of traffic signal control to install at a particular location, the method of accomplishing the work, the warrants upon which the authorization was based, and the funding source. When executed by the district, the form also serves as:
  • authorization for the existence of the signal
    and
  • authorization to do the work under certain programs where work authority has not been previously granted.
Districts are authorized to program projects directly with the Transportation Planning and Programming Division (TPP). In order to obtain a valid control-section-job (CSJ) number to establish a project, the district must submit a signed Traffic Signal Authorization Form to TPP.
Signature Requirements.
 The following officials’ signatures are required on the Authorization Request Form:
  • recommendations by district traffic section
  • approval by the district engineer.
Disposition of Paperwork.
 TxDOT policy requires districts to keep all relevant paperwork in their files. Traffic engineering data need
not
 be submitted to TRF.

Recommending Against Installation

When the district’s traffic study indicates that a traffic signal is not needed, the district should notify the requesting party, by letter, that a traffic signal installation is not recommended. In unusual cases, the district may wish to submit their traffic study to TRF for review and comment prior to notifying the requesting party of the study results.

Removal of Traffic Signals

Although the original installation of a traffic signal may be based on the satisfaction of one or more warrants and other factors, changes in traffic flow over time may reduce the effectiveness of traffic signal control. When this occurs, it may be appropriate to remove a traffic signal. The
TMUTCD
 provides the following guidance regarding the removal of traffic signals:
"If the engineering study indicates that the traffic control signal is no longer justified, and a decision is made to remove the signal, removal should be accomplished using the following steps:
  1. Determine the appropriate traffic control to be used after removal of the sign.
  2. Remove any sight distance restrictions as necessary.
  3. Inform the public of the removal study.
  4. Flash or cover the signal heads for a minimum of 90 days, and install the appropriate stop control or other traffic control devices.
Remove the signal if the engineering data collected during the removal study period confirms that the signal is no longer needed.”
Before determining to remove a traffic signal, keep in mind that it is possible that a signalized intersection that does not meet any of the warrants will meet at least one warrant after the signal is removed (due to increases in crashes, delay, or traffic patterns). Therefore, the removal of a traffic signal requires engineering judgment.
Due to the expense associated with the removal and possible re-installation of a traffic signal, the following steps should be followed prior to the removal of a traffic signal:
  1. The traffic signal should be placed in flashing operation reflecting two-way or multi-way stop control, as appropriate.
  2. If, after an extended period of flashing operation, intersection operation and safety is acceptable, the signal should be deactivated and STOP signs should be installed on the appropriate approaches. Signal deactivation can be accomplished by covering the signal heads, turning them face down, or removing the signal heads completely. Signal related signing should be removed from the intersection. The signal poles, mast arms, and span wire should be left in place.
  3. After an extended period of acceptable sign control operation, the signal poles, mast arms, and span wire should be removed.
TRF may be consulted for guidance when removal of a traffic signal is being considered.

City Traffic Signal Installation Using Local Funds

When a city of 50,000 or greater population (latest federal census) desires to install a traffic signal using local funds within its corporate limits on a highway of conventional design which is on the state highway system, TxDOT must conduct a traffic study to determine
  • if there is a need
  • if warrants are met
  • if the proposed installation should be authorized.
When the district engineer approves the project by signing the Traffic Signal Authorization Form, the district should then forward a copy of the signed authorization form to the city to serve as their record of approval for the proposed traffic signal installation.

Project Cancellations or Change

If for any reason the work from an approved project is not to be performed or the method of performing the work is to be changed (such as from state forces to contract or vice versa), the district should advise the Transportation Planning and Programming Division (TPP).