Startup Idea: People Counting Software for Truck Stop Restaurant

Startup idea to develop a software solution which can interface with an infrared device to count people entering and exiting a large travel center restaurant. The software should provide daily, weekly, monthly, and annual statistics, and predict future traffic.

We are looking for a software solution for our large travel center (Truck stop), in which we can tally the average traffic for our resteraunt, (in and out), by finding or using some device with infared that counts people coming in the door and out (it would be a straight across laser line that people can't see, the restraunt is inside and there are no swinging doors, they just walk into the area), that would hook up to the computer and count the number of people that go in and out and give average totals for a day, week, month, year and prediction of customers in and out per day or any given time. Thanks!. Yes, nothing good.