Help!

Hello,
I am making a project for school. It will be a robot that will help blind people cross streets. If the robot gets to a curb, it will sense if there is any motion . If none for 5 seconds, it will move across the street. How can I do this? Is there any code I can look at that is similar to what I want to program? I know Java but I don't know C++.
I already have the motion sensor.

How can I make the code so that if there is no motion, the robot will move in a straight line?

Please please help!

Mac
(Da n00b)

If the robot gets to a curb, it will sense if there is any motion .

How will it determine that it has gotten to a curb?

Motion where? What is moving?

If you are seriously expecting the robot to detect cars whizzing by, you need another project. You are out of your depth on this one.

Yeah, wow, take a deep breath and analyze the complexities here. PaulS is pointing out very valid but only a handful of possibly countless situations you need to handle.

Break down your task ( learn C++ ), prepare for a long haul, there is more than just learning to program C++ required to complete a project like this. To analyze a busy street you will need multiple tasks running simultaneously with complex signal processing, not to mention everything else. Keep this as a project for when you have enough mileage in the required range of skills.