Intelligent Speed Assistance: an on-road evaluation
DOI:
https://doi.org/10.55329/qopq5888Keywords:
Intelligent Speed Assistance (ISA), Northern America, Safe System approach, speed management, vehicle technologyAbstract
Although approximately 29% of traffic fatalities involve excessive speed, individual vehicle technology that can reduce speeding has not been widely studied or implemented in the United States (U.S). Starting in 2022, NYC DCAS conducted the largest public pilot of active Intelligent Speed Assistance (ISA) in the U.S., with approximately 400 vehicles equipped with a device that prevents acceleration when the vehicle is traveling faster than a preset threshold over the speed limit (typically 11 mph). Using an “opportunity to speed” framework (i.e., only account for driving time when a driver is traveling at least 5 mph below the speed limit), an analysis of 270 vehicles equipped with ISA showed there was a 64.18% relative decrease in the time driven >11 mph over the posted speed limit following ISA activation compared to before activation. This decrease in time spent speeding was not seen in non-equipped control vehicles. Speeding drive time reduction ranged from ~50% on 25 mph local roads, which have speed safety cameras set to the same enforced speed threshold, to 77% reduction on 50 mph roads. In addition, the impact of ISA on speeding behaviour of habitual speeders in 130 vehicles was similar to that on the primary cohort, indicating active ISA is effective at significantly reducing severe speeding across a wide range of drivers and fleets.
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Author Biographies
Alexander K. Epstein, U.S. Department of Transportation, John A. Volpe National Transportation Systems Center, the United States of America
Alexander K. Epstein is a senior engineer at the U.S. DOT Volpe National Transportation Systems Center in Cambridge, MA. Alexander leads transportation sustainability and vulnerable road user safety research spanning local, state, and federal transportation agencies. He oversees research partnerships with fleets, industry, and nonprofits to assess the safety and sustainability benefits of improved vehicle design and technologies. Alexander holds a doctorate in engineering sciences and masters in applied physics from Harvard University in Cambridge, MA.
CRediT contribution: Conceptualization, Funding acquisition, Methodology, Supervision, Writing—original draft, Writing—review & editing.
Sarah Yahoodik, U.S. Department of Transportation, John A. Volpe National Transportation Systems Center, the United States of America
Sarah Yahoodik is an engineering psychologist at the U.S. DOT Volpe National Transportation Systems Center in Cambridge, MA. Dedicated to improving transportation safety through research, Sarah has worked in the field for 10 years. At the Volpe Center, Sarah conducts multimodal human factors research across surface transportation and aviation, including work on distracted driving, advanced driver assistance technologies, and HMI design evaluation. Sarah holds a doctorate in human factors psychology from Old Dominion University in Norfolk, VA.
CRediT contribution: Formal analysis, Methodology, Writing—original draft, Writing—review & editing.
Alyssa Brodeur, U.S. Department of Transportation, John A. Volpe National Transportation Systems Center, the United States of America
Alyssa Brodeur is an engineering psychologist at the U.S. DOT Volpe National Transportation Systems Center in Cambridge, MA.
CRediT contribution: Writing—original draft, Writing—review & editing.
Juwon Drake, U.S. Department of Transportation, John A. Volpe National Transportation Systems Center, the United States of America
Juwon Drake is a general engineer at the U.S. DOT Volpe National Transportation Systems Center in Cambridge, MA. Juwon comes from a transportation planning and design background, focusing on safe street policy and design. At the Volpe Center, Juwon supports tasks requiring analysis of large data sets, including in safety research, emissions modelling, and climate hazard modelling. Juwon holds a master's in transportation systems engineering from the Georgia Institute of Technology in Atlanta, GA.
CRediT contribution: Formal analysis, Software.
Tomomi Landsman, New York City Department of Citywide Administrative Services, the United States of America
Tomomi Landsman is a fleet safety analyst at New York City Department of Citywide Administrative Services. She works to analyse telematics and collision data to determine safety trends and the effects of safety improvements on the City fleet. Tomomi holds a masters in Population Biology from University of California, Davis.
CRediT contribution: Data curation, Formal analysis, Software, Visualization, Writing—review & editing.
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Copyright (c) 2026 Alexander K. Epstein, Sarah Yahoodik, Alyssa Brodeur, Juwon Drake, Tomomi Landsman
This work is licensed under a Creative Commons Attribution 4.0 International License.
