Quick Facts
|
Fleet Vehicles Equipped |
500 |
|
Total Miles with ISA Enabled |
2.93 million |
|
Agencies Involved |
19 |
|
Light / Medium / Heavy Split |
69% / 17% / 14% |
|
Overall Reduction in Severe Speeding |
64.2% |
|
Expansion Planned |
+1,600 vehicles (USDOT grant) |
Source: VOLPE/NYC DCAS
In 2024, the NYC Department of Citywide Services (DCAS) equipped 500 municipal fleet vehicles with active Intelligent Speed Assistance (ISA) devices that limit acceleration above a set threshold beyond the posted speed limit.
The system uses GPS-based mapping to determine local speed limits and automatically prevents further acceleration once the vehicle reaches the programmed threshold. Drivers can temporarily override the system for up to 15 seconds when necessary (e.g., merging or emergency situations).
The program achieved measurable reductions in severe speeding across all road types and driver cohorts. This data was sourced from a report published in October 2024 and produced by DCAS in conjunction with the U.S. DOT Volpe Center.
Impact on Habitual Speeders
Comparison of time spent >11 mph over limit (30 days before and after activation)
|
Period |
% of DrivingTime >11 mph Over Limit |
|---|---|
|
Pre-ISA |
80% |
|
Post-ISA |
40% |
Even chronic speeders cut their severe speeding nearly in half after ISA activation (49%).
Source: VOLPE/NYC DCAS
Driver Improvement Rates
Percent of vehicles showing improved speed behavior after ISA activation
|
Cohort |
% of Vehicles Improved |
|---|---|
|
Worst 50% (Primary Cohort) |
94.8% |
|
Best 50% (Primary Cohort) |
76.7% |
|
Worst 50% (Habitual Speeders) |
96.7% |
|
Best 50% (Habitual Speeders) |
67.2% |
Nearly all of the highest-risk drivers improved, proving ISA is most impactful for the fleet’s worst offenders.
Source: VOLPE/NYC DCAS
Severe Speeding Reduction by Speed Limit
Percent decrease in time spent driving >11 mph over the limit
|
Posted Speed Limit (mph) |
% Reduction in Severe Speeding |
|---|---|
|
25 mph |
49.7% |
|
30 mph |
54.6% |
|
35 mph |
64.1% |
|
40 mph |
53.8% |
|
45 mph |
77.2% |
|
50 mph |
81.9% |
ISA was most effective on higher-speed roads, cutting extreme speeding by more than 80%.
Source: VOLPE/NYC DCAS
