If pushing the fan gets it started (not a coincidence that it started when you pushed it), then I think it's the fan. Would make sense that it is overheating in traffic if the fan isn't running.
Right on, thank you for your time sir.Anything mechanical can break and the fan lives in a rough environment. It isn't unusual for an electric fan to need replacement, like everything else in the car the supplier cuts costs to the bone to make profit. Even mil/space rated components have a non-zero failure rate and it is much higher for consumer products given the cost constraints.
Prior to electric fans, I have had to replace three fan clutches on vehicles I owned in the 6 to 8 year old range.
As I recall, there are two different cooling fan wattage levels based upon the engine and optional equipment/package so make sure if you replace it yourself that it is the proper one for your model.
You are welcome! And although replacing broken parts is never fun, it sounds like you diagnosed the problem quickly which often isn't the case with overheating; it is often an intermittent condition that never occurs when it is easy to diagnose.Right on, thank you for your time sir.