Which open source software can measure the speed of vehicles which drive along a street and pass two barriers A and B with a known distance?

The ASCII sketch shows the camera which is far away and records the scene nearly perpendicular. oRo is the vehicle, which is detected by the software.

     A                        B
     |                        |
---  |  ---     ---     ---   | ---
 oRo |        ->              |


I know many closed source solutions, but I am looking for an open source solution by intention.

2 Answers 2


What you are describing was developed in 1966 by a real estate investor and uses simple math to determine vehicle speed and was known as VASCAR. I can attest from experience that one can measure time passed during a one-quarter mile traverse and divide 3600 by the number of seconds to get the speed over that distance. Of course, one would want to maintain a steady speed. This was easy many years ago, as highways often had quarter mile markings to facilitate this practice, as well as to permit law enforcement in aircraft overhead to do the same! Other applications of this principle involved knowing the distance between two highway overpasses and measuring the crossing time of a vehicle traversing the span and performing the math. The referenced article makes note of a computer, which seems peculiar, as it is simple division and little else.

For your purposes, one with sufficient programming skills could use OpenCV to determine when a vehicle crosses the two locations. That would be the tricky portion, in my opinion, as the timing portion would follow naturally using internal clocks of the computer being used.

You would have complications if more than one vehicle was in the frame at the same time, but if the OpenCV was sufficiently powerful to distinguish between vehicle shapes and/or colors, it might yet be managed.

  • If I assume, that there one vehicle in one section, per lane at maximum, it gets much easier. To program. But I guess, I am not the first person with this idea and the open source software already exists. I think "You can write this software your self" is not a real answer as software recommendation. Dec 26, 2017 at 0:52
  • 1
    I was unable to find open source or commercial versions of video based VASCAR, although there are plenty of references to law enforcement using video to record VASCAR results. My answer is based on the concept that a solution can be found using OpenCV but would require user programming ability. It's a better answer than "NONE."
    – fred_dot_u
    Dec 26, 2017 at 1:52
  • 1
    Additional research using terms such as "video trigger race timing" has produced no useful results specific to the original post. The results would indicate that there are programmers with sufficient skill to create the requested software, but that such software does not yet exist. Some open source programs for timing races are found, but do not use video to trigger start/finish. I expect that those creators would have the skill needed to meet the requirements of the original request, but have not yet done so.
    – fred_dot_u
    Dec 26, 2017 at 11:36

I know the question is tagged linux - but there IS a windows system that does exactly this. If you google ngsim, ng-video, and FHWA, you will find info on the ng-video system released in 2006, which was used for automated traffic volume counting, displaying a table of vehicle speed (not just average) for each vehicle. It's not open source, or linux, I know. But there are contacts you will find in your search results who may be interested to hear that it should be open sourced, but if not, certainly would want people to be using it (I don't believe it was ever intended to cost anything). There is also sample data available, though it is so large, it may not be downloadable. To be honest - my initial search didn't uncover a link to download the actual system, but I think if you contact the people at FHWA you find in these links, they may point you to that.

After you do that, if you need additional assistance, I can see if I can help. I have a vested interest in it - I wrote the system.

  • Forgot to mention - the ng-video system is based on OpenCV
    – Nate Clark
    Dec 26, 2017 at 12:39
  • It might be worth trying to run it under Wine
    – Mawg
    Jan 8, 2018 at 12:28
  • Nate, do you have a URL for that?
    – Mawg
    Aug 31, 2018 at 9:08

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