DCAS has now expanded its use of its intelligent speed assistance (ISA) technology to 500 vehicles from 19 agencies and offices, with 23 distinct types of vehicles, including heavy trucks.

The expansion of the ISA initiative includes 158 cars identified as high-risk units due to regular speeding. 

How ISA Works and What It's Doing

Intelligent speed assistance is an active technology that prevents a vehicle from speeding wherever it operates in the city or beyond. ISA does not engage a vehicle's brakes to stop speeding. ISA prevents a vehicle from further accelerating once it is traveling at or above the posted speed limit or a different limit that DCAS can set. 

DCAS often sets vehicles at 11 miles per hour above the posted speed limit to help with driver adoption and transition to the technology. 

To date, medium- and heavy-duty trucks account for 31% of the vehicles using ISA and 36% of the 2.9 million miles that NYC Fleet vehicles have traveled with ISA engaged. DCAS' expansion to 1,600 more vehicles was done through the support of a Federal DOT grant.

Targeting High-Risk Vehicles

For the first time, DCAS also focused the rollout on vehicles identified as high risk due to repeated speeding and red light camera tickets or high-risk driving behavior identified through risk monitoring from the DCAS Fleet Office of Real-Time Tracking. In February 2024, Washington DC became the first city in the United States to mandate this technology for at-risk drivers.

DCAS and US DOT Volpe conducted a control group study to assess further ISA's effectiveness for all vehicles, especially the high-risk units. In the control group study, vehicles with ISA were compared to comparable vehicles without ISA. 

The analysis reviewed 894,983 miles of driving and over 51 million total records. The analysis did not focus on all miles driven. Instead, the assessment was for all miles with an "opportunity to speed." Volpe found that only 21% of all miles represented an opportunity to speed and focused the ISA analysis on those miles.

Despite narrowing the analysis in this way, DCAS and Volpe found a 64% improvement in speeding behavior using ISA compared to not using ISA. The improvements in speed were more significant for roadways with higher speed limits. The benefits of ISA also held for those most at-risk vehicles with histories of speeding and more reckless driving.