Seat Belt Wearing in Scotland - A Study on Compliance - Research Findings

DescriptionThis report was commissioned to obtain a reliable measure of the extent to which seat belts and other restraints are currently used in Scotland by car, taxi and light van occupants.
ISBN0 7480 6943 7
Official Print Publication Date
Website Publication DateFebruary 11, 1999
Development Department Research Programme Research Findings No. 47 (1998)
Seat Belt Wearing in Scotland-A Study on Compliance

Halcrow Fox

ISBN 0-7480-6943-7Publisher The Scottish OfficePrice £5.00
The protection from death and serious injury in road accidents provided by seat belts has been widely recognised since front seat belt wearing became legally enforceable in Great Britain in January 1983. Research studies by Transport Research Laboratory (TRL) in England have consistently found high rates of driver and front seat passenger compliance and lower rates for rear seat passengers. The Scottish Office commissioned Halcrow Fox to obtain a reliable measure of the extent to which seat belts and other restraints are currently used in Scotland by car, taxi and light van occupants.
Main findings
  • 86% of all vehicle occupants were observed to be using an appropriate restraint.
  • Taxi and light vans occupants had substantially lower compliance rates than car occupants.
  • There were differences between car occupants' use of restraint according to seating position, with 94% of drivers, 92% of adult front seat passengers and 55% of adult rear seat passengers being appropriately restrained.
  • In addition to rear seat passengers, front seat male passengers aged between 14 and 59 and male drivers in the 17 to 29 age range had relatively low compliance rates.
  • The rate for children aged between 5 and 13 years who were restrained in the rear seat of cars was 74%.
  • Scottish based compliance rates were slightly higher than the comparable data from the TRL research in England - for car drivers (+5%) and rear seat passengers (+8%).
  • There was a correspondence between the behaviour of car passengers and drivers, with a greater likelihood of passenger compliance where the driver also used a seat belt.
  • Compliance rates were measurably higher in the summer than the spring for the three sites observed in both time periods.
  • There was no evidence that compliance rates were sensitive to factors such as the weekday time of travel or the speed limit in operation.
Background
The protection provided by seat belt wearing against death and serious injury has been widely recognised since front seat belt wearing was introduced as a legal requirement in Great Britain in January 1983. Further legislation in 1989 and 1991 required children and adults to use rear seat restraints, where these are available. Research studies by TRL in England have consistently found high rates of driver and front seat passenger compliance and lower rates for rear seat passengers.
The research on compliance levels has mostly been carried out in England and there was a need to establish a clearer picture of seat belt use in Scotland. The Scottish Office Central Research Unit therefore commissioned Halcrow Fox to carry out surveys of seat belt wearing at a range of sites representative of Scotland in April and May 1997, with a more limited follow-up survey in July 1997.
The Scottish Study
The overall aim of the research was to obtain a reliable measure of the extent of use of seat belts and other restraints in Scotland. The objectives may be stated as follows:
  • to highlight differences in the level of compliance according to occupant position within the car (front or rear occupant);
  • to establish differences between gender and age groups in terms of level of compliance;
  • to ascertain whether compliance levels vary according to traffic conditions, road type and geographical location, and
  • by comparing patterns in Scotland with the rest of Great Britain, to ascertain whether further research is required to explore reasons for non-compliance.
Methodology
The data required to achieve the Study aim and objectives were collected by observing behaviour at a sample of sites which were representative of Scotland, and consisted of 21 sites in or near Glasgow, Edinburgh, Aberdeen, Dundee, Inverness, Stirling, Dumfries and the Borders.
At each site vehicle details and occupant characteristics and behaviour, with respect to seat belt compliance, were observed between 0700 and 1900 on a single day in April or May 1997. The surveys at three sites were repeated in July 1997 to determine the variation of compliance with seasonal change.
The method used to collect these data closely resembled the TRL methodology and involved the observation of vehicles and occupants which were stopped on the approach to one arm of a signalised junction.
Survey Report
In the spring survey, seat belt compliance was observed for 43,108 persons travelling in 30,076 out of a total of 80,956 vehicles (a sample proportion of 35.8%). These surveys achieved the aim of providing a substantial and reliable dataset for further analysis. This compared with the TRL April 1997 surveys, where a total of 42,308 persons were observed travelling in 27,980 vehicles.
The repeat summer surveys at three sites observed 3,278 out of 4,178 vehicles (78.5%) containing 5,951 occupants. This higher proportion sampled was due to the lower traffic flows at two of the sites and a higher number of occupants per vehicle.
Results
Vehicle Type
Across all sites 86.4% of vehicle occupants were observed to be using an appropriate restraint. Of the 30,076 vehicles observed, about 90% of the vehicles sampled were cars, 2% taxis and 8% light vans. Figure 1 shows that the level of compliance amongst light van and taxi occupants was relatively low.
Figure 1 : Use of Restraint by Vehicle Type
Seating Position
Analysis of restraint in cars by seating position, shows that restraint was used by 26,754 drivers (94%), 7734 front seat passengers (92%) and 1504 rear seat passengers (55%).
Age, Gender and Seating Position
Figure 2 shows that the 5 to 13 and 14 to 29 age groups have compliance rates which are low compared to other age groups.
Figure 2: Use of restraint by age of car occupant
Figure 3 combines the results on gender and seating position. There is a small, significant overall difference between male (90%) and female (93%) compliance rates. The diagram shows that for all seating positions female compliance rates exceed those for males. This difference is 5% for drivers, 8% for front seat passengers and 13% for rear seat passengers.
Figure 3: Use of Restraint by Gender and Position in Car
A detailed analysis of compliance rates by age, gender and seating position showed that the following had the lowest rates:
  • all male and female rear seat passengers aged 14 and over, whose restraint percentages range between 39.3% and 65.5%;
  • front seat male passengers in the 14 to 59 age range (between 80.7% and 88.6% of occupants wearing restraint);
  • male drivers in the 14 to 29 age range (87.2% of occupants appropriately restrained).
Driver and Passenger Restraint
The results show that in cars where the driver used a seat belt, 89.2% of passengers were properly restrained. This contrasts with the remaining cars where only 27.4% of passengers were properly restrained, a difference of over 60%. This evidence suggests a correspondence between driver and passenger behaviour. Intuitively it seems likely that passenger behaviour is influenced by driver attitude to seat belt wearing.
Comparison with England
A comparison of the Scottish based results of this study and the TRL April 1997 results as presented in the TRL information leaflet, 'Restraint Use by Car Occupants 1995-1997' (LF 2076, August 1997) showed that the Scottish compliance rates were consistently higher. The results are shown in Figure 4.
Figure 4: Comparison of TRL/SO Restraint Use by Position in Car
Regional Differences
The results show a significant difference between (former local authority) regions in the percentage of car occupants using appropriate restraints. In the Central Belt, approximately 88% of car occupants used an appropriate form of restraint. The percentages for the rest of Scotland were higher, and ranged between 94.1% and 96.3%. These differences do not appear to be explained by differences in the gender and age distribution within sites.
Spring and Summer Compliance Rates
There was a measurable increase in the use of restraint on all three sites of about 5% for two sites, and of 13% at the third. The major factors affecting this change were the increase in the proportion of cars making up the traffic flow (car occupants have much better compliance rates than other vehicle occupants), and the increase in compliance rates for car occupants when compared with levels observed on a weekday.
Other Factors
There was very little variation in the overall compliance rate amongst car occupants according to the time of day. The overall percentage of car occupants who used an appropriate restraint, ranged between 89.9%, and 92.1% during the survey day.
The results showed a greater level of compliance with seat belt legislation on 'A' class trunk roads (93.1% use restraint) than for 'C' class and unclassified roads (87.3%). There were however, few 'C' class roads used in the surveys. There was no evidence to suggest a relationship between restraint use and the speed limit.
Conclusions
The following groups should be considered for targeting in future road safety campaigns:
  • taxi and light van occupants;
  • rear seat passengers over the age of 13. Although these represents a small proportion of all car occupants, the levels of compliance were very low in comparison to other car occupants;
  • front seat male passengers in the 14 to 59 age range, and
  • male drivers in the 17 to 29 age range.
There is evidence of a relationship between driver and passenger behaviour and this should be further investigated to determine whether there is a causal link between these two groups of car occupants.
The limited spring and summer comparison suggested greater compliance levels in the summer. Further research should be considered into compliance rates according to journey purpose and day of travel.
"Seat Belt Wearing- A Study on Compliance", the Research Report summarised in this Research Findings, is available price £5.00.
Cheques should be made payable to The Stationery Office and addressed to:
The Stationery Office Bookshop,
71 Lothian Road,
Edinburgh EH3 9AZ
Telephone: 0131-662 7050, or Fax: 0131-662 7017

The report can also be ordered online from:www.thestationeryoffice.co.uk

Further copies of this Research Findings can be obtained from:
The Scottish Office Central Research Unit,
Area 2J, Victoria Quay,
Edinburgh EH6 6QQ
Telephone: 0131-244 7560