How can I divide the highway into segments

I am working on simulation of grouping vehicles on the highway. I want to divide the highway with specific length and width into four or five segments and in each segment there are random number of moving vehicles (groups) which mean grouping vehicle according to the length of the street like dividing the street to parts and in each part or cluster I will have a number of vehicles. Can you please help me and tell me how can I simulate it in Matlab code.