I am doing a school project which involves creating an automated gate which responds to light as well as another form of energy. I am fairly sure of what to do for the basics of the circuitry and the mechanisms, but there are some aspects of the circuitry I am not so sure. Here is the basic schematic of the design I created:

Could you give me advice on how to use incorporate limit switches into the circuit (as it's a bi-fold swing gate, it will need 4). Or would a timer circuit work better?
Also, would it be feasible to use multiple reed switches or a programming chip so that the gate can open at night when a vehicle approaches?
Would this be OK for the limit switches?

 

Reed switches can carry only a small current so would not handle motor current.
Think about how much power you will need to move a heavy gate at a certain speed, choose a suitable motor with appropriate gearing, then select switches suitable for the peak (stalled) motor current.
Your light-operated circuit needs hysteresis to prevent erratic operation with slight changes in light level.