Scottish Government

THE SPEEDING DRIVER: WHO, HOW AND WHY?

Normal speed, preferred speed and knowledge of speed limits

7.14 Respondents had indicated (Table 7.1) what they thought the speed limit would be on each of the 7 roads. A detailed picture of the speeding behaviour of Scottish drivers may be compiled by comparing their nominated 'normal' speeds with both the actual speed limit (those whose normal speed exceeds the actual limit being termed 'objective speeders') and their own intimated speed limit (those whose normal speed exceeds their estimate of the speed limit being termed 'subjective speeders') across all 7 road types.

7.15 Table 7.5 shows the normal and preferred speeds for the three road types where respondents' estimates of the speed limit were most commonly wrong: the dual carriageway, the wide residential road and the country road. While misperceptions about the speed limit might explain why some drivers reported normally driving and preferring to drive at a speed lower than the actual speed limit, it is also plain that some drivers who are driving at the speed limit ('objective compliers') actually think they are speeding.

Table 7.5: Normal and preferred speeds of drivers giving most common speed limit estimates

7.16 This data is further summarised in Table 7.6 which gives, for each estimate of the speed limit, the percentage of drivers exceeding what they think the speed limit is for that road.

Table 7.6: Percentage of drivers who's nominated normal and preferred speeds exceed own estimate of the speed limit

7.17 Thus, for example, on the wide suburban road (P3), two-thirds of those who think the speed limit is 30mph report a normal speed (66%) and a preferred speed (64%) in excess of 30mph.

7.18 Do these figures vary by driver gender or age? Further detailed analysis was performed to show the proportions of objective and subjective speeders by age group for each gender. The figures for 'objective speeders' - those drivers whose nominated speed at which they would normally drive is in excess of the actual (objective) speed limit - are given in Table 7.7.

Table 7.7: Objective Speeders. The percentage of each age group whose normal speed exceeds the actual speed limit for 7 road types, separately for male and female drivers

7.19 For male drivers there were significant age effects for all the faster roads (P1-P3, P7) but no age effects for urban roads (P4-P6) and the 21-29 age group had the highest proportion of 'objective speeders' on 6 of the 7 road types. For female drivers there were significant age effects on all roads save P6, the narrow residential street, with more of the 21-29 age group speeding on fast roads (P1, P2, P7) and the 17-20 age group speeding most on urban roads (P4, P5).

7.20 The contrast between male and female drivers is summarised in Table7.8, giving the percentage of each gender whose normal speed is above the speed limit for each road, and showing the p value for a chi-square comparison of the two distributions.

Table 7.8: Objective Speeders. The percentage of male and female drivers whose normal speed exceeds the actual speed limit for 7 road types

7.21 The proportion of males whose normal speed exceeds the speed limit for that road is significantly greater than that for females on fast roads (P1, P2, P7), but the proportions do not differ on slower roads.

7.22 Table 7.9 summarises the contrast between male and female drivers for each age group, averaging across all 7 road types.

Table 7.9: Objective Speeders. The mean percentage of each age group whose normal speed exceeds the actual speed limit averaged across 7 road types, separately for male and female drivers

7.23 The figures show equivalent numbers of young (17-20) and older (60+) male and female objective speeders, with more male than female speeders in each of the intermediate age groups (21-59). As many young and old females are exceeding the speed limit as age-equivalent males, though amongst the 17-20 age group more males than females speed on fast roads and more females than males speed on urban roads (Table 6.23).

7.24 The figures for 'subjective speeders' - those drivers whose nominated speed at which they would normally drive is in excess of their estimate (subjective) speed limit - are given in Table 7.10.

Table 7.10: Subjective Speeders. The percentage of each age group whose normal speed exceeds their estimated speed limit for 7 road types, separately for male and female drivers

7.25 There are significant age effects for the males on the three fastest roads (P1, P2, P7) with more of the 21-29 age group wanting to drive above the speed limit on motorway and rural A road, and more of the 31-39 age group on dual carriageway. For the female drivers there were age effects for motorway and dual carriageway driving (P1, P2) and for the main road in town (P4) with more of the 21-29 age group on the fast roads and more of the 17-20 age group on the urban road wanting to go faster.

7.26 There were significant differences in preferred speed between male and female drivers on motorway, dual carriageway and main road in town, but not on the other road types.