Driving change in car safety regulation

“Our work involves looking at the relationship between humans and machines, and how Intelligent Speed Assistance systems can be implemented to improve road safety.” Professor Oliver Carsten, Institute for Transport Studies

Simple and low-cost adaptations to existing new car systems could reduce road accidents, injuries and deaths. Using existing cameras, GPS and processing power that most modern vehicles already possess, Intelligent Speed Assistance (ISA) could be achieved for around €20 per vehicle. 

The primary challenge is in securing public and political acceptance and this is where research by Leeds Institute for Transport Studies (ITS) has made a difference.

ISA systems work through GPS, cross-referencing with digital road maps and available visual cues, such as road signs, to provide speed limit information for each road. They process information and pass it on to the driver to help monitor and manage speed. The vehicle takes on some of the work – and responsibility – from the driver. 

Evidence on the behavioural and safety impacts of ISA from ITS has played a significant role in the advance of vehicle regulation and an effective step change in road safety performance.

The European Commission is currently working to enforce a central policy to ensure that new vehicles are fitted with advanced safety features, including ISA. The formal set of proposals for a new set of minimum safety standards was informed by the prior studies, including from ITS. 

“This has been referred to as the biggest intervention since compulsory wearing of seatbelts and will probably be more effective than that,” explains Professor Carsten. “The estimate is that a minimum of 25,000  lives will be saved over the evaluation period but this is conservative. We are talking about an extremely important safety package.” 

For a long time though, it looked as if ISA would be the best system we never had, and that such safety measures would remain a pipedream. 

A long journey to impact

Since 1995, Oliver Carsten, Professor of Transport Safety, and colleagues at ITS, have worked to establish the life-saving potential of ISA systems. 

It began with an EPSRC grant, which funded research to assess how drivers were affected by the presence of ISA systems. The research took place in a driving simulator and focused on attitudes to speed, and speed compliance in urban environments. The results suggested that ISA led to a reduction in maximum speeds, particularly in low-lit areas and at speed limit transition points. 

Between 1997-2000, working with the Motor Industry Research Association (MIRA), the ITS team explored the behaviour of real world drivers with ISA in their cars. The result is still the most comprehensive study, anywhere in the world, on the impacts the system has on behaviour, traffic patterns and accident risk.  

Supporting this was a cost/benefit analysis of ISA, and its potential not only to save lives, but to save money too. Each fatal road accident costs the UK taxpayer over £1.6m; any reduction in crashes could save significant sums.  But the technology was not yet available to make widespread ISA use a reality. 

Professor Carsten explains: “By the late 1990s we realised that the safety impact could be huge. In particular, modelling work we did in 1999 indicated that many lives could be saved, but the technologies needed to deliver ISA were still too futuristic.”

The evidence continued to build, and in 2003 the Department for Transport funded a Field Operational Test in the real world. Twenty cars were adapted by MIRA and data collected by the Leeds University team on the everyday driving of almost 80 drivers in both rural and urban settings. All categories of drivers, including those who admitted a tendency to speed, had improved speeding behaviour when driving with ISA across a variety of road categories. 

Environmental impact

As well as safety implications, the environmental impacts were estimated, using data generated in earlier research. Funded by the Commission for Integrated Transport and the Motorists’ Forum, in 2007 Carsten and his team reanalysed the data from the Field Operational Test, using up-to-date national fuel models to estimate the impact of ISA on emissions and fuel economy. Speed limitation generated an immediate 5% fuel saving for motorway driving. 

From research to reality

By this point, the evidence was clear. Any further research risked stalling legislation, as instead of relying on what had been done, policymakers could wait to see what the next trial or analysis said. 

Professor Carsten explains: “There was a time after the completion of the last project looking at environmental and safety benefit, where it looked like nothing would happen. It was good to see it come back and attract attention from all the major stakeholders.”

Today, ISA is one of three injury crash prevention technologies adopted by the European New Car Assessment Programme. This has encouraged automobile manufacturers to rapidly adopt the current safety features available for new models, and as of 2013, almost 70% of all new cars being tested by Euro NCAP were fitted with speed assist systems, double the number in from the previous year.

And the European Commission is currently moving towards making Intelligent Speed Assistance (ISA) systems a mandatory feature for almost all vehicle types. Across Europe, this could save at least 2,000 lives every year. 

“It feels good to make a difference. There is satisfaction to have had an influence on actual road safety and that is greater than the academic satisfaction of writing good papers. If this goes through then there is extra reward for me to know that lives have been saved,” says Professor Carsten. 


  1. Comte, S.L. (2000) New systems: new behaviour? Transportation Research Part F: Traffic Psychology and Behaviour, 3(2): 95-111. doi: 10.1016/S1369-8478(00)00019-X. 
  2. Lai, F., Carsten, O. & Tate, F. (2012) How much benefit does Intelligent Speed Adaption deliver: An analysis of its potential contribution to safety and environment. Accident Analysis and Prevention 48  63–72. doi:10.1016/j.aap.2011.04.011
  3. Carsten, O. & Tate, F. (2005) Intelligent speed adaptation: accident savings and cost–benefit analysis. Accident Analysis and Prevention, 37(3): 407-416. doi: 10.1016/j.aap.2004.02.007