Here is our report on the traffic video provided by:

Traffic Video date: 2^nd September 2002                                                System Type: ProVida

Constabulary: South Yorkshire

Summary

• The Traffic Officer was performing a pre fed distance check over 0.2 of a mile and the officer utilised "VASCAR" markers on the carriageway.
• The traffic video has recorded the speed of another vehicle 92.42 mph and the officer decided not to pursue this motorist.
• As the officer was parked some distance from the carriageway, it is not possible to positively identify the 'target vehicle' from the traffic video.
• The ProVida system may have been malfunctioning because the speed of the patrol car is recorded as varying from 74 mph - 21 mph - 23 mph and back to 70 mph during a period of one second; which is impossible.
• We have performed a time and distance measurement from the time the officer finished his pre fed distance check to the time that he caught up with the 'target vehicle'.

For ProVida system information please follow this hyperlink.

Time and Distance speed-measurement during patrol car pursuit

Time (T2 - T1) = 135.08 seconds - 53.96 seconds

Time = 135.08 - 53.96 = 81.12 seconds

Distance in miles (D2 - D1) 85.295 - 83.485 = 1.810 miles

Average speed of 80.25 mph over 1.810 miles

Time 1 - Time when the officer stops the pre-fed distance check at the second VASCAR marker

Distance 1 - Odometer reading when the patrol car is approaching the second VASCAR marker

Time & Distance 2 - The patrol car is the same distance from the target vehicle as it was from the second VASCAR marker

Reading of previous vehicle - 92.42 mph

Patrol car speedometer variation

Patrol Car "catching up"

Start of pre-fed distance check

End of pre-fed distance check