|Recent research has found that the installation of camera equipment at signalised junctions in Glasgow has resulted in a reduction of red light running and associated accidents at the camera sites. The Scottish Office commissioned Halcrow Fox to investigate whether the use of red light cameras in Glasgow District has created wider benefits, including a reduction in the number and type of accidents at all signalised junctions across the whole of the district, and not just at the specific camera site localities. The period studied covered 3 years before and 3 years after the installation of cameras.|
- There was a significant decline in accidents at all signalised junctions in Glasgow between the before and after periods studied.
- Both personal injury and non-injury accidents caused by red light running fell by about a third.
- Red light cameras appeared to be only one of several factors contributing to the reduction of accidents at signalised junctions. Red light running accidents accounted for 20% of the decline.
- Changes in accidents due to other causes were more significant, particularly accidents caused by pedestrians "crossing carelessly" which account for 44% of the reduction in personal injury accidents.
- Injury accidents caused by red light running declined more sharply at junctions away from the camera sites suggesting that factors such as junction improvement, traffic management and increased vigilance were also important.
- The reduction in red light running accidents cannot be attributed to changes in traffic flows during the study period.
- Results from a Cost Benefit Analysis suggest that the economic returns from the implementation of red light camera technology in Glasgow District have been positive.
|The Strathclyde Police Red Light Initiative was formulated in the late 1980s with the objective of promoting road safety and reducing road accidents. This was in anticipation of the 1991 Road Traffic Act (eventually implemented in Scotland in 1993) which enabled the use of automatic detection devices in the enforcement of road traffic law. As part of this initiative, red light cameras were installed, and by 1995 there were 8 camera sites at signalised junctions and 3 at pelican crossings in Glasgow District. Previous research has studied the link between red light running and accident causation and found that 17% of personal injury accidents at signalised junctions in Glasgow District were primarily caused by red light running. Recent research has found that cameras significantly affected driver behaviour at the camera sites, leading to a large reduction in the incidence of red light running, and a fall in accidents at the camera sites.|
|To develop this work further, The Scottish Office commissioned Halcrow Fox to investigate the possible wider effects of camera technology on all signalised control junctions in the Glasgow district. Specific objectives of the research included: |
- to determine the characteristics and frequency of accidents at signalised junctions and near pelican crossings for time periods before and after the introduction of cameras
- to assess the impact of the cameras on the number and type of accidents at all signalised junctions and pelican crossings within Glasgow District
- to examine the results in the light of national and regional trends in accidents, and of changes in traffic flows in Glasgow District, to determine whether broader trends may be responsible for the observed changes
- to estimate the benefits and costs of using camera technology in relation to any reduction in the number of accidents.
|The research was based on a statistical analysis of data which was drawn from different sources, and the study involved three distinct stages; firstly, the collection of accident, traffic and camera related cost data; secondly, the processing and analysis of that data; and thirdly, the use of the results to estimate the costs and benefits of camera technology.|
|National trend data on personal injury accidents only were drawn from the data series Road Accidents Scotland published annually by The Scottish Office, and were compared to the incidence of personal injury accidents occurring in Glasgow during the study period.|
|Strathclyde Regional Council provided data on all accidents (injury and non-injury) at junctions and near pedestrian crossings in Glasgow district for the period January 1989 to November 1995, along with data on traffic flow.|
|Analysis of the accidents at signalised junctions was divided into 3 distinct time periods: |
'Before' - January 1989-June 1991, before cameras were introduced.
'Interim' - July 1991-March 1993 when the cameras were in use but before the legislation allowing camera evidence was enacted; warning letters only were issued.
'After' - April 1993-November 1995 when the cameras were used with fixed penalty fines.
|Different time periods were used for accidents at pelican crossings, and for comparison purposes the results were presented as accident rates per month.|
|A cost benefit analysis was made by estimating the cost of purchasing and operating the camera system compared with any reduction in accident costs. This was estimated over a 20 year period and discounted to 1993. Outputs are in terms of 1998 prices and 1993 values.|
|Figure 1 below shows that there has been a broad downward trend in personal injury accidents since 1989, but by 1994 the rate of decline in the number of accidents in Glasgow was greater than for Scotland as a whole.|
|Figure 1 |
Personal injury accidents and traffic 1989-1995
|Accident trends within the study area are broadly in line with Scottish accident trends, and the overall decline in accidents for Scotland of approximately 20% between 1989 and 1994 compares with a decline in accidents at all signalised junctions in Glasgow of 25% and in accidents at all pelican crossings in Glasgow of 30% over the same period. The substantial drop in the number of accidents in 1993 is not matched at national level and coincides with the introduction into full operation of Strathclyde's first red light camera.|
|Accidents at signalised junctions in Glasgow district|
|Over the study period, the number of all accidents at signalised junctions reduced by 2,260, with fatal accidents reducing from 27 in the before period to 8 in the after period, serious injury accidents from 466 to 248 and slight injury accidents from 1,665 to 1,061. The number of non injury accidents reduced from 4,579 to 3,160. Table 1 below describes the changes in accident severity by rates per month. The downward trend in these accidents is reflected in national figures for built up areas.|
|Table 1 |
Accident Severity at Signalised Junctions by Time Period (Rate per Month)