Connecticut laws/regulations; Background;

OLR Research Report

June 4, 2012




By: Paul Frisman, Principal Analyst

You asked whether (1) state law requires large volume traffic generators, such as shopping malls, to obtain State Traffic Commission (STC) certification, (2) the STC has the authority to review such a development, and order changes made, if the development exceeds its traffic volume estimates, and (3) such a review has occurred. You also asked how traffic estimates are made.


State law requires certain large developments to get a certificate of operation from the STC. This applies to certain people, businesses, or state or municipal agencies building, expanding, establishing, or operating an open air theater, shopping center, or other development generating a large volume of traffic that substantially affects state highway traffic (CGS 14-311). The law does not define what constitutes a major traffic generator, but STC regulations specify that a development is subject to the above requirements if it has (1) 200 or more parking spaces or (2) a gross floor area of at least 100,000 square feet (Conn. Agencies Regs. 14-312-1).

The STC, in deciding whether to issue a certificate, must consider highway safety, the width and character of affected highways, traffic density and character, and the opinions and findings of local traffic authority. It may require the developer to pay for traffic signals, pavement markings, traffic channelization, pavement widening, or other changes or traffic control devices STC determines are needed to handle traffic safely and efficiently.

Improvements or Changes

According to STC Transportation Supervising Engineer James M. Jurczyk, all STC certificates include a condition that the STC reserves the right to require additional improvements or changes, as deemed necessary, if the actual traffic volume or distribution differs so substantially from the projected volume or distribution that additional mitigation is required. The owner must pay for any additional improvements or changes. Jurczyk said he is not aware of this condition ever being used.    


Traffic Estimates

According to Jurczyk, traffic estimates are based on trip generation rates (the number of trips beginning or ending in a particular area) developed by the Institute of Transportation Engineers (ITE) for a specified land use. (ITE is an international association of transportation professionals.) He said the generation rates are based on actual counts of developments with similar land uses throughout the country, and have proved reliable. There have been cases where a proposed land use does not fit any of the ITE land use generation rates.  In those cases, the state Department of Transportation (DOT) has typically asked the developer to develop a generation rate based on data the developer collects from a similar land use in Connecticut or elsewhere in the U.S. He said these practices ensure that the generation rates are not exceeded later. 

Jurczyk says DOT's experience has been that the actual traffic volume for a certified development prepared in this way rarely exceeds the original estimates. Consequently, he said, the review of certificates at some point in the future for a comparison of projected versus actual counts is not considered warranted.


Prior to July 1, 2012, the STC, among other responsibilities, established a uniform system of traffic control signals, devices, signs, and markings for use on public highways, and regulated the use of state highways and roads on state-owned property. Its members are the commissioners of the transportation, motor vehicles, and emergency services and public protection departments, with the economic and community development commissioner participating on matters pertaining to economic development (CGS 14-298).

PA 12-132, effective July 1, 2012, eliminates the STC and creates an Office of State Traffic Administration (OSTA) within DOT as STC's successor agency. The act transfers to OSTA most of STC's duties and powers, including oversight of large volume traffic generators. For more information, please see the bill analysis for PA 12-132 (HB 5170) at: http://www.cga.ct.gov/2012/BA/2012HB-05170-R01-BA.htm.