ARC 9875C

ARC 9875C

TRANSPORTATION DEPARTMENT[761]

Notice of Intended Action

Proposing rulemaking related to traffic signal synchronization
and providing an opportunity for public comment

    The Transportation Department hereby proposes to rescind Chapter 143, “Traffic Signal Synchronization,” and to adopt a new Chapter 143, “Traffic Signal Coordination,” Iowa Administrative Code.

Legal Authority for Rulemaking

    This rulemaking is proposed under the authority provided in Iowa Code section 364.24.

State or Federal Law Implemented

    This rulemaking implements, in whole or in part, Iowa Code section 364.24.

Purpose and Summary

    This proposed chapter lays out requirements regarding the installation and coordination of traffic signals.

Regulatory Analysis

    A Regulatory Analysis for this rulemaking was published in the Iowa Administrative Bulletin on October 15, 2025. A public hearing was held on the following date(s):

     ?   November 6, 2025

    The Department received no comments.

Fiscal Impact

    This proposed rulemaking has no fiscal impact to the State of Iowa. Local public agencies bear the costs of installing and maintaining traffic signal coordination equipment and services.

Jobs Impact

    This proposed rulemaking maintains an already established requirement that certain traffic signal installations within a city be operated in a coordinated manner.

Waivers

    Any person who believes that the application of the discretionary provisions of this rulemaking would result in hardship or injustice to that person may petition the Department for a waiver of the discretionary provisions, if any, pursuant to 761—Chapter 11.

Public Comment

     Any interested person may submit written comments concerning this proposed rulemaking, which must be received by the Department no later than 4:30 p.m. on January 27, 2026. Comments should be directed to:

Public Hearing

    Public hearings at which persons may present their views orally will be held as follows:

    Persons who wish to make oral comments at a public hearing may be asked to state their names for the record and to confine their remarks to the subject of this proposed rulemaking.

     Any persons who intend to attend a public hearing and have special requirements, such as those related to hearing impairments, should contact Ryan Pell and advise of specific needs.

Review by Administrative Rules Review Committee

    The Administrative Rules Review Committee, a bipartisan legislative committee which oversees rulemaking by executive branch agencies, may, on its own motion or on written request by any individual or group, review this rulemaking at its regular monthly meeting or at a special meeting. The Committee’s meetings are open to the public, and interested persons may be heard as provided in Iowa Code section 17A.8(6).

    The following rulemaking action is proposed:

    ITEM 1.  Rescind 761—Chapter 143 and adopt the following new chapter in lieu thereof:

CHAPTER 143

TRAFFIC SIGNAL COORDINATION

761—143.1(364) Definitions.

    “Arterial street” means any U.S. or state numbered route, controlled access highway, or other major street or highway designated by the city within its respective jurisdiction as a part of a major arterial system of streets or highways.

    “Coordination” means the establishment of a timing relationship between adjacent traffic signals.

    “Traffic signal” means any permanently installed, electrically powered traffic control device by which traffic is alternately directed to stop and to proceed.

    “Traffic signal system” means two or more traffic signals operating in a coordinated manner.

761—143.2(364) Applicability. This chapter applies to all cities with more than three traffic signals within the corporate limits.

761—143.3(364) Conditions.

    143.3(1) Unless a traffic engineering study documents that it is not practical, traffic signals within one-half mile of each other along an arterial street or in a network of intersecting arterial streets shall be operated as a traffic signal system.

    143.3(2) Traffic signal timing and operational plans are to be developed by the application of traffic engineering principles to provide maximum traffic flow efficiencies and safety for all users.

    143.3(3) All traffic signal installations and operations are to comply with the department’s traffic control device manual.

761—143.4(364) Contact information. Information regarding this chapter is available from: Traffic and Safety Bureau, Iowa Department of Transportation, 800 Lincoln Way, Ames, Iowa 50010. Additional information and guidance may be found at www.iowadot.gov/consultants-contractors/traffic-safety/document-resource-library/traffic-safety-manual.

These rules are intended to implement Iowa Code section 364.24.