Oversight of Selected Aspects of Traffic Controls (Follow-Up)

Issued Date
April 11, 2024
Transportation, New York City Department of


To determine the extent of implementation of the 11 recommendations included in our initial audit report, Oversight of Selected Aspects of Traffic Controls (Report 2018-N-6).

About the Program

The New York City Department of Transportation (DOT) is responsible for the operation and condition of approximately 6,300 miles of streets and highways, over 12,000 miles of sidewalks, more than 13,250 signalized intersections, and over 315,000 street lights. This includes conducting traffic control studies at intersections, approving traffic controls (including traffic signals and multi-way stops), and overseeing the design, construction, timing, and maintenance of traffic control devices.

DOT is responsible for conducting traffic control studies at intersections with and without traffic signals. DOT receives intersection study requests from various sources, including the City’s 311 system, the DOT website, letters from the public, elected officials, and DOT employees. DOT also develops data-driven lists of non-signalized intersections to be studied as a proactive initiative.

DOT’s Traffic Management Center (TMC) is a 24/7 operation responsible for citywide traffic management, incident response, traffic signal operation and maintenance, and information dissemination. To monitor traffic conditions and detect incidents, TMC staff use video surveillance cameras and media broadcasts. DOT is also part of the Joint Transportation Management Center, which coordinates incident response with its Office of Emergency Response, the New York City Police Department, and the New York State Department of Transportation.

Midtown in Motion (MiM), a congestion management system, is used by TMC to improve traffic conditions in midtown Manhattan by identifying traffic issues and automatically adjusting signal patterns to smooth traffic flow. The TMC operator can override the MiM proposed changes. According to DOT officials, MiM manages over 500 signalized intersections utilizing 160 microwave sensors, 50 traffic video cameras, and 100 E-ZPass readers.

The objectives of our initial audit, issued on September 30, 2020, were to determine whether DOT monitors and evaluates traffic flow at intersections and whether DOT took action to improve safe traffic and pedestrian flow at intersections. The audit covered the period from January 1, 2016 to March 13, 2020.

The audit found that DOT monitored traffic flow at intersections but did not address the concerns of its customers in a timely manner. Among the issues we found:

  • Our review of 78 intersection studies determined it took DOT an average of 10 months (41 weeks) to complete a study – well beyond the 4-month time frame specified in DOT’s Resource Guide – with 34 studies taking more than 1 year to complete.
  • We visited 17 intersections where DOT recommended improvements and found six improvements that were not implemented, and no evidence of the decisions made by DOT regarding the recommended improvements.
  • The TMC did not always monitor traffic conditions due to traffic cameras that were pending repair for significant amounts of time, including 35 traffic cameras that were out of service for over 180 days, with two traffic cameras out of service for over 5 years.

Key Findings

DOT officials made some progress in addressing the issues we identified in the initial report. Of the initial report’s 11 recommendations, five were implemented, four were partially implemented, and two were not implemented.

Key Recommendation

DOT officials are requested, but not required, to provide information about any actions planned to address the unresolved issues discussed in this follow-up within 30 days of the report’s issuance.

Carmen Maldonado

State Government Accountability Contact Information:
Audit Director: Carmen Maldonado
Phone: (212) 417-5200; Email: [email protected]
Address: Office of the State Comptroller; Division of State Government Accountability; 110 State Street, 11th Floor; Albany, NY 12236