Evaluation of Moving Mode Radar for Speed Enforcement in Victoria, 1995-1997

Monash University Accident Research Centre – Report #141 - 1998

Authors: K. Diamantopoulou, M. Cameron, M. Shtifelman

Full report in .pdf format [4.8MB]

Abstract:

During 1995 the Transport Accident Commission (TAC) purchased 30 new moving mode radar (also known as mobile radar) units for installation in Victoria Police patrol cars to supplement the 18 existing units operated by the Police since August 1994. The new units became operational on 29 June 1995. In 1996, a further 25 moving mode radar devices were purchased by the TAC, bringing the total devices used by Police in Victoria to 73. A television advertisement pertaining to the mobile radar enforcement was launched by the TAC during November 1996.

The effect of mobile radar enforcement and supporting publicity on road trauma during July 1995-June 1997 was examined in terms of the number of casualty crashes that occurred on undivided roads in 100 km/h speed zones in Victoria. The crash-based analysis compared crash frequencies for the period in which up to 73 mobile radar devices were operational (July 1995-June 1997) with the corresponding two-year period before their introduction (July 1992-June 1994) when there was no moving mode radar enforcement.

The evaluation found evidence of a four-day residual enforcement effect on casualty crashes in rural areas of Victoria during July 1995-June 1997, but the effect diminished five to seven days after the enforcement’s presence. The strongest effects on casualty crashes in rural Victoria occurred when the enforcement was accompanied by high awareness levels of specific mobile radar publicity. The largest crash reductions occurred one to four days after the enforcement was present in a particular region of rural Victoria. Under these circumstances, a 28% decrease in casualty crashes resulted which was marginally statistically significant. Crash reductions were also evident when high awareness levels of general speed-related publicity accompanied the mobile radar enforcement. However the effects were smaller and weaker than those produced when the publicity support was specific to the mobile radar enforcement. There was no evidence of crash reductions in the outer metropolitan regions where mobile radar was used.

The findings suggest that, in rural areas of Victoria, mobile radar enforcement is an effective tool for reducing casualty crashes on undivided highways. The results also suggest that publicity supporting the mobile radar enforcement produces stronger effects when it is specific to the enforcement rather than when it encompasses all speed-related themes.

Executive Summary

During 1995 the Transport Accident Commission (TAC) purchased 30 new moving mode radar (MMR) units for installation in Victoria Police patrol cars to supplement the 18 existing units operated by the Police since August 1994. The new units became operational on 29 June 1995. The moving mode radar units are used on two-way, undivided, 100 km/h speed limit roads from a moving patrol car, primarily in rural areas where the approaching traffic is travelling in a near-parallel (but opposite) direction.

In 1996, a further 25 mobile radar devices were purchased by the TAC. These 25 units became operational in late June 1996, bringing the total of mobile radar devices used by Police in Victoria to 73. A television advertisement pertaining to the mobile radar enforcement was launched by the TAC during November 1996.

This study, carried out under MUARC’s baseline research program, aimed to document the enforcement activity and publicity awareness levels achieved, and to estimate the effects on road trauma on the enforced roads during July 1995-June 1997.

Enforcement Activity

During July 1995-June 1996 when there were 48 MMR devices in operation, a total of 47,136 hours of operation was achieved or about 902 hours per week on average. For July 1996-June 1997 when there were 73 MMR devices in operation, the total number of hours achieved was 47,148 or 904 hours per week on average. Thus there was little difference between weekly average hours of operation for the two 12-month periods even though during July 1996-June 1997 there were 25 more MMR devices in operation. The operational effectiveness of MMR activity was measured as the number of offences detected per hour of operation. During July 1995-June 1996, the monthly rate on average was 0.68 offences per hour. However, during the following 12-month period, the monthly rate had increased to 0.83 offences per hour.

Publicity Supporting Moving Mode Radar Enforcement

During the period of moving mode radar use examined in this report, July 1995-June 1997, a television advertisement specific to the new mobile radar technology was first launched by the TAC in November 1996. This advertisement was shown in both metropolitan and rural areas of Victoria. In addition, there were other advertisements relating to the general speeding theme shown in both regions during the two-year period of the evaluation.

Effects on Road Trauma

The effect of the increased moving mode radar enforcement and supporting publicity on road trauma during July 1995-June 1997 was examined in terms of the number of casualty crashes that occurred on undivided roads in 100 km/h speed zones in Victoria. The crash-based analysis compared accident frequencies for the period in which the new units were operational (July 1995-June 1997) with the corresponding two-year period before their introduction (July 1992-June 1994) when there was no MMR enforcement.

This initial analysis established that there was little or no effect beyond four days after the enforcement was present. The findings showed evidence of a four-day residual enforcement effect on casualty crashes for mobile radar operations in rural areas of Victoria, but the effect diminished on the fifth, sixth and seventh day after the enforcement’s presence. In addition, the preliminary findings gave no evidence of crash reductions in the outer metropolitan regions where mobile radar was used. Thus, the subsequent crash effects were measured only for rural areas of Victoria.

Assuming a four-day residual effect, the strongest effects on casualty crashes in rural Victoria occurred when the MMR enforcement was accompanied by high levels of specific mobile radar publicity awareness during November 1996-June 1997. The effects were strongest one to four days after the enforcement was present in each particular region of rural Victoria. Under these circumstances, a 28% reduction in casualty crashes was found which was marginally statistically significant. An 11% reduction was also found for crashes occurring on the same day as the enforcement, however this reduction was not statistically significant. When low awareness levels of mobile radar publicity accompanied the enforcement, crash reductions were not evident.

For the one-year period (July 1996-June 1997), when the enforcement was accompanied by high awareness levels of general speed-related publicity (including mobile radar publicity), the strongest effects on crashes in rural Victoria also occurred one to four days after the enforcement. The effects, however, were weaker than those produced when the publicity was specific to the style of enforcement. Under these circumstances, an 11% reduction in crashes was found, but this decrease was not statistically significant.

For the combined two-year period (July 1995-June 1997), the effects were also strongest when the general speed-related publicity accompanying the enforcement was at high levels of awareness. An 8% reduction in crashes was found one to four days after the enforcement was present under these circumstances in rural Victoria. This reduction was not statistically significant, however. Interactions of the MMR enforcement with the specific mobile radar publicity were not examined for the two-year period because there were no mobile radar advertisements prior to November 1996.

The findings suggest that, in rural areas of Victoria, mobile radar enforcement is an effective tool for reducing casualty crashes on undivided highways. The results also suggest that publicity supporting the mobile radar enforcement produces stronger effects when it is specific to the enforcement rather than when it encompasses all speed-related themes.

Sponsoring Organisation: Baseline Research Program - Department of Justice, Transport Accident Commission, Royal Automobile Club of Victoria (RACV) Ltd, VicRoads