Measuring speed of moving vehicles with pic?

i have a project about this.i want to use infrared distance sensors.i know i can measure distance at least 2.i ll use long range distance sensors.i want this drivers can see their speed at a display.anybody help me how can i do this?

The IR you ae measuring cannot measure more than 5cms... what is the range your IR setup is measuring. how do you relate the speed of vehicles using IR.. its practically wrong... either go for ultrasonic or SONAR sensors available in the market...

i found some long range ir sensors mikroepsilon and many other companies.but im not any information about their prices but i think they are expensive.i need help about it.

I suggest that you go with ultrasonic sensors. I recommend the PING ultrasonic sensors from Parallax. They're super easy to use. They're 30 dollars apiece the last time I checked.

i have used gps module in the past to make speedometer for quad,buy at surelectronic Gps Dev board,only 35$...
10$ for Gps module and 5$ for antenna.
hope this help

i want to measure speeds of all cars from near the road and i want to use sensors.anybody want to help me?

Mostly these displays use microwave doppler, similar to a police speed trap, laser time of flight could work too. Ultrasonic would be difficult over the required distance, it's also affected by wind.

Ultrasonic speed sensing can use doppler measurement similar to an ultrasonic burglar alarm. Unfortunately, the doppler shift at higher car speeds would exceed the bandwidth of usual sensors. A parabolic reflector could collimate the sensor wave to a small angle and achieve larger measurement distances.

P.S.: mikroepsilon has industrial laser time of flight sensors, but they are actually expensive. They are not designed for speed measuerements, but most likely fast enough to calculate speed from varying distance. Thess are basically point sensors, you possibly would want a wider angle of view for your sensor.

Said Parallax Ping sensors are specified for maximum 3 m operation distance :sad:
Parallax X band movement detectors specified for 9 m distance are operating based on doppler effect, but designed as a switch without a frequency output. Supplementing a similar device with a sensitive amplifier and a frequency detector, and possibly a reflector may work.