In 2022, the City of New York initiated a small pilot study to evaluate the effectiveness of Intelligent Speed Assist in tackling dangerous speeding. Today, it has rolled out the technology to 700 vehicles across various City agencies, the largest project of its kind in the world. NYC Chief Fleet Officer Keith Kerman explains how the City is improving safety by slowing down.
In the US, speed is a major factor in traffic fatalities. As per figures from the National Highway Transportation Safety Administration, speeding plays a role in at least 29% of traffic fatalities each year, causing more than 11,000 deaths.
Through Vision Zero, NYC is taking steps to address speeding, including lowering the speed limit to 25 mph or lower; expanding bike lanes and re-designing roadways to limit speeds and calm traffic through our New York City Department of Transportation; and enforcement measures through the New York Police Department. In 2014, NYC lowered the speed limit citywide from 30 mph to 25 mph. Sammy’s Law, passed by NY State in 2024, allows the City to reduce speed limits even further to 20 mph in high-risk locations.
These measures are critical to tackling speeding. But what if vehicles were designed so they wouldn’t speed in the first place?
The NYC Department of Citywide Services (DCAS) is implementing this type of technology as part of its Vision Zero Safe Fleet Transition Plan.
DCAS has already been innovating in speed monitoring. Through the Fleet Office of Real Time Tracking, DCAS live tracks 29,000 vehicles each day, monitoring speed and excessive speeding, as well as other safety indicators, including seatbelt use, hard acceleration, hard braking, hard cornering (the ABCs of safe driving), and crashes. This has enabled DCAS to achieve a major 70% reduction in excessive speeding through monitoring and immediate follow-ups with drivers and reduce overall risky driving behaviour, crashes, and injuries.
However, DCAS wanted to go further. Most vehicles have speed governors that prevent the vehicle from going at extreme speeds. Was there a way to combine the speed governor and telematics tracking and keep vehicles at the speed limit at any specific location? This is intelligent speed assistance (ISA).
Intelligent speed assistance
ISA is a technology that uses telematics to monitor vehicle locations with mapping of speed limits. When a vehicle attempts to speed beyond the limit in any location, ISA will prevent the engine computer from sending a signal to the vehicle accelerator. ISA can be set at the speed limit, above or below. DCAS gives most employees in our programme an 11-mph buffer above the speed limit, which matches the buffer for speed camera tickets.
The DCAS ISA programme does not brake a vehicle, which can be a startling experience for a driver. Instead, it prevents further acceleration once the speed limit has been matched or exceeded. There is also a button that allows the driver to suspend ISA operation for 15-second intervals to address unexpected situations.
In 2022, DCAS launched a pilot of 50 ISA units. In December of the same year, DCAS published initial findings showing that vehicles were staying within speed limits throughout the system and that risky driving was reduced.
DCAS has since expanded the system to 700 vehicles, the largest project in the world, including more than 21 different agencies and 23 types of vehicles, including trucks and school buses. This fleet has driven more than six million miles using ISA. At the Agency for Children Services, the entire fleet uses ISA.
DCAS has an 11-year partnership with the US Department of Transportation Volpe Centre to study safe and clean vehicle design, and the two organisations have partnered on a control group study of ISA to determine its benefits.
Some critical approaches informed the study. As we all know, compliance with speed limits is often a product of heavy, congested traffic. The study excluded those periods, focusing only on times when a vehicle had the opportunity to speed. In addition, the study took a special look at high-risk vehicles – those with a history of speed violations as tracked through telematics or high instances of speeding or red-light violation tickets.
The study found a 68% reduction in speeding among units equipped with ISA. Just as importantly, there was a 50% reduction in speeding even with the high-risk units, demonstrating that ISA slowed down even those drivers most bent on dangerous speeding.
The use of ISA to address ‘super speeders’ has now gained national attention. Virginia, Georgia, and Washington, DC have passed laws to install ISA on high-risk drivers as a law enforcement tool. New York State and others are looking at similar legislation.
DCAS is now taking it further. In October, at its 10th Annual Fleet Safety Forum, DCAS announced that ISA would be installed as a standard feature on all civilian light-, medium-, and heavy-duty trucks going forward. The programme will include over 7,000 trucks and will be the largest ISA rollout to date.
In recognition of its Safe Design and ISA efforts, the National Safety Council presented DCAS with its National Safety Excellence Award, the Green Cross, in September 2025. The National Safety Council is the oldest and largest safety organisation in the United States.
DCAS is also leading the nation in telematics and truck side-guards, surround and backup cameras, automated braking, driver alerts, and more to improve safety. Mayoral Executive Order 39 of 2024 is modelled after the London Direct Vision Standard and takes on visual impairment for truck operators for the City fleet and also contractors to the City.
Excessive speed is one of the greatest dangers in the roadway transportation system. Over the decades, many approaches have been pursued to reduce the harm caused by speeding. ISA may offer the most effective mechanism yet, re-designing the vehicle so it can’t and won’t speed in the first place.
