If your oil is getting over 230F or so during normal operation (and, yeah, sitting in traffic on a 90-degree day is considered normal operation) than the engine has a problem somewhere.
Start with the simple stuff: check to make sure your fan is working correctly, nothing blocking air flow. Make sure your engine tin is tight, and the whole underside of the motor is sealed from the top side—all the way around and front to back. If there are gaps anywhere, plug them, bend the metal to close the gap, or/and get new metal and rubber seals to make the gap history.
Sitting in traffic like that, ambient heat from your exhaust and the road below could be fining its way back into your fan shroud and recirculating.
Make sure your oil cooler isn't clogged or blocked off.
Once that's all done, if it doesn't solve it, take your heads' temperature during operation.
Also: Check your valve lash. An unlikely culprit here, but a tight exhaust valve can make a serious hot spot on that head, and if they're all too tight you might see oil temps come up.
Check the carbs to make sure you don't have a lean condition at idle. Super rare on a VW hot rod but it could happen.
The men who actually know something about these engines will chime in presently to correct and augment this advice.