Its not the goal to make a complete Bike Computer, merely to create some the internal circuits for measurements.
The most important functions (those to implement first) should be.

Distance = The number of pulses from the Reed-Relay * the circumference of the wheel
Velocity   = Related to the time it takes the wheel to make one turn.
                  Consult the owners manual to your own Bike Computer and get inspired

Secondly should the userinterface be implemented with the presentation of the collected data.

How to get the Reed Relay signal:

1. Use one the buttons at the kit - with a little practice should it be possible to match the frequency.
2. Create a build-in signal generator in you design with a variable frequency.
3. Use a external frequency generator if available - Please notice the voltage levels

The Game starts when you releases the Button (B) and the Led On After a random time (interval ....?.....) will the Led go Off and the Counter starts and will wait for your second press at B.

One the challenges in this project will be the random time and the State Machine which controls the game.
You should add a "Best score" remember functionality to the game as well.

You properly seen those tubes at the road - whenever the statistics wanted. In some roads can you even find permanent measurement in form of coils embedded in the asphalt.

If you consider the Velocity to be constant as the Vehicle passes the A and B will it be possible to calculate the Length of the passing Vehicle. In other word can prove that trucks driving much to fast during the night.