Understanding Inappropriate High Speed: A Quantitative Analysis

Marked individual differences were found in preferred speeds, frequency and extent of speeding and speed choice around speed cameras. These differences related to driver sex, age, motivations and collision involvement but not to knowledge about the effects of higher speeds.

Inappropriate high speeds (IHS) are associated with increases in crash probability and severity, and we need to understand why they happen if we are to design workable interventions.

Around 17% of drivers say they enjoy driving fast and that it will always be difficult to keep down to the speed limit.

13% say they are fully compliant with speed limits; 7% said they exceeded all of the limits at least once in the previous three months by the largest margins specified.

Females, older drivers and low mileage drivers are more compliant, as well as drivers of cars with smaller-sized engines out of town.

Drivers may be categorised by how they behave around a speed camera in a 30 mph zone. About 60% are conformers and stay at or below the limit. 11% are compliers who approach at a higher speed, slow down at the camera and then stay at or under the limit. However, 29% of males and 22% of females are manipulators: they drive faster than the limit, having passed the camera.

30% of drivers reported that they have recently reduced their driving speed in town and 25% out of town. About 13% of drivers say they become more aggressive behind the wheel.

Drivers significantly overestimate the time gained by driving faster than 60 mph and the time lost by driving more slowly than 60 mph.

One-third of drivers agree that they do not always know the speed limit of the road they are driving on.

The majority of drivers seem to be aware of the effects of speed on crash frequency and severity.

On the open road, most respondents agreed that, if they drove any faster than their preferred speed, they would feel less in control, the task of driving would be more difficult and it would feel too risky.

A typology of speeders was identified. Excessive speeders are more likely to be male, young, drive faster than others and have more collisions.