I'm an amateur when it comes to working on cars but I'd like to learn how to fix my own car.

I have a 2001 Mitsubishi Mirage DE. My car functions great even after all these years and I've been the only owner. If I get on the freeway and I don't run into heavy traffic, the car works fine. If I get on the freeway and I do run into traffic where I have to start and stop a lot (switch from 2nd to 3rd), the temp gauge begins to move to hot but the car doesn't behave if the engine is overheating and no dashboard lights come on. Also, if I use the service roads, I still don't have the problem unless I have to wait at a light for a really long time or I have to start and stop a lot (switching between 2nd & 3rd gear).

1) Is there a way to replicate this issue without driving?
2) What could the problem be? I thought the car might actually be overheating but once the car starts moving again the temp gauge returns to normal unless I have to slow down again.

Shawn