Evidence gaps hamper Vision Zero ambitions

Cities are struggling to prevent road collisions because they lack evidence about near misses, driver behaviour and traffic conflicts, despite having access to historical crash data, according to new research.

The report, Emerging Themes for Vision Zero Cities, by Silicon Highway Solutions, draws on 15 submissions from transport leaders, who attended the Transport Innovation Alliance forum held in London on 30 September to 1 October 2026.

“We weren’t testing whether cities are committed to Vision Zero, they clearly are,” Nadeem Ullah, Director of Programme Management at Silicon Highway Solutions, told Cities Today. “We wanted to find out where progress actually stalls: a lack of ideas, evidence, powers or [a lack of] agreement. The clearest answer was that it is rarely a lack of ideas.”

Of the 15 submissions, 11 indicated that cities held collision data, but only one reported having continuous sensor data. Delegates frequently identified missing information about driver behaviour, near misses and vehicle speeds.

“Collision data is, by definition, a record of harm that has already happened,” Ullah said. “To move from reacting to preventing, cities need to measure the conflict, not just the crash.”

Junctions and crossings

Junctions and crossings were the most frequently identified concern, accounting for seven submissions. Pedestrians were at risk in all seven cases and cyclists in five. Although every city reporting these problems held collision data, delegates highlighted gaps in understanding dangerous interactions.

“Delegates told us what they were missing: the driver’s perspective, the motivation behind red-light running, how often near misses happen, and the circumstances of each crash,” Ullah said.

The report also highlights trade-offs between safety, traffic capacity and public acceptance. One city wanted to reduce collisions without significantly affecting junction throughput, while another was considering road redesign, closing side streets and driver education.

School safety emerged as another concern, with three submissions identifying conflicts during drop-off and pick-up periods. None held collision data, despite reporting regular conflicts involving children, vehicles and deliveries.

“The harm they describe is daily conflict that rarely becomes a recorded crash, so it barely shows up in the records used to justify investment,” he said.

Beyond traditional enforcement

The survey found that conventional measures, including traffic calming, speed cameras and policing, were proving insufficient for some cities. Eight submissions described problems concentrated during rush hours or school journeys, while two highlighted speeding on empty roads at night.

“One delegate wrote ‘police is powerless’; another, ‘speed cameras cannot be the only option’,” Ullah said. “What remains are decisions involving trade-offs, not missing tools.”

The report also found that 11 submissions identified Safe Streets as a priority, compared with four for Safe Vehicles and just one for post-crash response. Ullah argued that cities should involve organisations beyond highway authorities, including schools, police and fleet operators.

“Two cities can describe the same problem in almost the same words, yet need very different responses,” he said. “One may lack evidence; another may lack the powers to act on the evidence it has.”

Silicon Highway proposes helping cities define problems, establish evidence, assess trade-offs and agree measurable outcomes before implementing changes.

“What makes the difference is a disciplined way of moving from problem to decision,” he said. “Done this way, the right solution for a particular street comes out of the process rather than being assumed at the start. It also comes with the evidence a city needs to defend its decision and build on it.”

Silicon Highway will be at the Smart City Expo World Congress in Barcelona, 3–5 November, Hall 3, stand C171. To find out more, email nadeem@siliconhighway.com

Main image: Melpomenem | Dreamstime.com