Police Officer Preparation & Law Enforcement Resource - Archive

When an officer receives training for using time/distance detection equipment (VASCAR, Accutrak, etc.), is there a minimum distance recommended for effective use?

My son's science fair project is a demonstration of VASCAR, used in Pennsylvania by most local departments since they are not permitted to use RADAR. I'm setting up a computer simulator to allow the viewer to see what it's like to time vehicles and establish error margins.

I initially taped videos of different cars travelling a course of 100' marked by two milk jugs. But that distance seems way too short, hence my question. I sent an email to the manufacturer, but haven't heard back yet. I'm hoping they list a minimum distance in their manual that he can use.

Any help would be appreciated.

Every time I see VASCAR, I think it is a new form of NASCAR.

Hutch

I agree! :D

.1 of a mile is our minimum enforcement use distance.

Calibration is .25 of a mile.

We've still got 4 units, but haven't used them in years.

In PA there is no required distance.

I'll bet, if you call and ask nicely, the local police department would be interested in helping your son with his project. They might provide some information, or, if you are really lucky, demonstrate the device.

We use 528 ft or .10 mile for stationary speed timing. When using VASCAR in a mobile mode the distance is sort of a moot point for pacing.

Never heard of VASCAR. All radar and laser in TN. ;)

Everything you ever wanted to know about VASCAR (http://www.vascarplus.com/Pages/How_it_works.htm)

Just curious, but what are you Not Guilty of? I just thought your username was a little odd. Are you trying to beat a VASCAR ticket?

In my county the Dist. Magistrate will throw out any VASCAR if the distance is 100ft. My department uses 200ft. We callibrate at .25 mile.

Our handheld laser unit does the same thing. We can either shoot cars (the easy way), or use the distance/timing option.

.25 mile calibration.
usually clock at a minimum of .25 miles. max I have had is about 3 miles. margin of error is fricking small at that point.

THe manufacturer of VASCAR recommends a minimum distance of 200 feet. Legally there is NO mimimum distance though.

ANY "error" that the operator causes during the activation of the first switch ( as the vehicle passes the first mark) , is negated by the same " error" as the operator activcates the second switch ( as the vehicle crosses the 2nd mark).

There is an error formula in the operators manual which shows quite plainy how LITTLE a difference an error in distance perception makes based upon the distance of the course.

I believe in the .10 of a mile course, an error of 20 FEET amounts to approximately a 1 mph discrepancy. VAscar computes an average speed, not an exact speed like radar. It takes a LOT more to come up with a useable error than the operator being off by a few feet.

We lose precious FEW Vascar trials. :)

I think this whole idea has been motivated by a certain party getting a vascar cite.

Just curious, but what are you Not Guilty of? I just thought your username was a little odd. Are you trying to beat a VASCAR ticket?

I was thinking about that too.

Honestly, it did start out that way. I received a citation about a year ago and it really bugged me. I did a lot of research and talked to a lot of people in different law enforcement roles (constable, state troopers, lawyers, etc.) and I was convinced I had a good argument. The distance on my citation was 104'. Apparently, the small town, police chief is my brother-in-law magistrate thought it was good enough so I paid the fine. End of that story.

But that really did lead to this science project. I do believe VASCAR is an effective speed measuring device that's fair to the driver since it's an average speed over a distance, ASSUMING THAT DISTANCE IS FAR ENOUGH TO MINIMIZE HUMAN ERROR. (Capitalization added only for emphasis). I tend to agree with mcsap and seand442 that a longer distance eliminates that error and I'm hoping the data collected by his project will prove that.

Thanks to those who provided information regarding their training and manufacturers recommendations. I'm sure anyone who has been through training would agree that there is absolutely a distance that is just too short to get an accurate speed measurement.