...traffic. What can cause this? What can cause my engine temp go into the red in traffic and in stop and go driving. What can cause this and how much do u think this might cost me?
My radiator doesn't leak and the temp goes down if I turn the engine off for 5 min or so. This only happens if I sit in traffic or in very slow city driving conditions.

Check your fan operation. It may not be coming on. If you can drive in open air and it stays cool, the radiator, water pump and thermostat should be working. However, the fan has to keep the air moving through the radiator when you're stopped. Open the hood and see if the fan ever kicks on when you have it hot (especially as it climbs the temp gauge). Be sure to watch it for a few min (unless it gets too hot and you have to shut it off) because it will cycle between being on and off. If the fan does not ever turn, turn the A/C on, if the fan kicks on with the A/C, it's the temperature sensor (not to be confused with the temperature gauge sender). If the fan doesn't turn on even with the A/C on, it's the fan.