How Effective?

  • Advisory ISA was fitted to cars and buses in a recent trial in Lancashire, UK:
    • When drivers chose to activate the system, speeding was reduced by 30 per cent on 30 mph roads and by 56 per cent on 70 mph roads.
    • Being able to use the system (but not necessarily having it active) reduced speeding of the car drivers on 30 mph roads by 18 per cent and on 70 mph roads by 31 per cent.
    • For car drivers aged 25 and below, active use of advisory ISA resulted in a reduction in speeding of 22 per cent on 30 mph roads and 37 per cent on 70 mph roads.

(F. Lai et al., 2012)

  • A less recent on-road ISA trial in France found that:
    • Advisory ISA reduced the amount of time spent speeding by 10.5 per cent overall but there was a reduction of only 3 per cent on 50 km/h urban roads.

(J. Ehrlich et al., 2006)

  • An on-road ISA trial with 146 subjects was carried out in North Jutland, Denmark. The ISA was advisory (i.e. provided information via an audible warning) and had selectable added functionality: reduced speeding behaviour was recorded and resulted in incremental discounts applied to the cost of the subject’s insurance (i.e. incentive). The study found that:
    • When ISA delivered information only it was more effective than when it delivered incentive only.
    • When all drivers had a combination of information and incentive the overall proportion of speeding of then 5 km/h was 4 per cent, compared to 13 per cent in the baseline before period. However, there was a trend for this effect to wear off over time.

(H. Lahrman et al., 2012)

  • An on-road ISA trial in the Netherlands collected data on headway time to the vehicle in front as well as speed. An in-car display gave immediate feedback to the driver, who was given financial reward for good driving behaviour.
    • In the system-active period speeding was reduced considerably. The proportion of distance travelled below the speed limit increased from 68 per cent in the before period to 86 per cent in the first part of the supported period.
    • Activation of the system increased the percentage of distance travelled at safe headways from 58 per cent to 77 per cent.
    • However, the effects on speed and headway decreased notably after 11 and 19 weeks respectively.

(U. Mazureck and J. van Hattem, 2006)

  • A recent simulator study considered the effects of ISA on overtaking. From the 29 participants it was found that:
    • Mandatory ISA could affect the safety of overtaking manoeuvres, i.e. more unsafe behaviours were displayed such as ‘cutting in’ in front of the overtaken vehicle.
    • When driving with voluntary ISA, drivers disengaged the system in approximately 70 per cent of the recorded overtaking scenarios.

(Jamson et al., 2012)

  • A project considered design of on-board monitoring and reporting systems on commercial vehicles in North America. It selected five core behavioural categories which systems should monitor in order to be effective:
    • Speed selection (compared to speed limit, traffic flow, curve, gradient, road surface);
    • Following behaviour (following distance, driver response to cut-ins);
    • Attention / Inattention (road / lane departures, hard braking events, hard steering events, eyes off the road);
    • Fatigue (lane position keeping, hard braking events, hard steering events, eye closure, hours of service); and,
    • General safety (seat belt use, indicator use, checking blind spot, fuel economy, engine overspeed, gear selection, acceleration).

(Misener et al., 2007)

  • An on-road trial of teen drivers in rural North America used event-based video recording (where recordings were sent to subjects’ parents and events correspond to notable lateral or longitudinal accelerations). The before and after study showed that:
    • There was a significant reduction in safety related events. In the first nine weeks, these fell from 8.6 events per 1,000 miles (baseline) to 3.6 events per 1000 miles.
    • In the following nine weeks, the subjects further reduced the number of safety related events to 2.1 per 1000 miles; a 76 per cent reduction from the baseline.

(McGhee et al., 2007)

  • IVDR capable of auditory feedback and management reporting was installed in an ambulance fleet in Arkansas and Pennsylvania. The trial showed:
    • A 1000-fold increase in distance driven between reportable safety events, indicating a substantial improvement in driving safety behaviours.
    • A much greater improvement was evident when the device was configured to send reports to management.
    • The reduction in reportable safety events was sustained throughout the reporting phase, which lasted for three years.

(N. Levick, 2009)

  • A trial in the Netherlands showed that distance driven to a destination in an unfamiliar area reduced by 16 per cent when using a navigation system.

(Vonk et al., 2007)

Gaps in the research

  • A positioning system is an essential component of many telematics devices – Global Positioning System (GPS) is by far the most frequently used. However, the work by the Royal Academy of Engineers (2011) has identified particular vulnerabilities with GPS and suggests that safety critical systems be made more resilient to disruption or potential outages. The work by EuroRAP (2011) on intelligent roads makes only a high level attempt to provide an alternative.

  • This synthesis has uncovered little academic research considering the safety case of satellite navigation system use.

  • Similarly, there is little academic research on the safety case for e-call, and none that is directly applicable to the particular scenarios encountered in the UK.

  • Date Added: 03 Apr 2012, 08:18 AM
  • Last Update: 09 May 2013, 02:35 PM