Hyundai Repair: rpm surging, throttle position sensor, driveability

Question
I have a 2002 accent that has rpm surging at any speed. Idle, intown, highway...whenever. Getting worse. No check engine light or any other faults. Will come back to normal RPM in seconds usually, but I have had to stop and turn off engine if it doesn't clear itself. Always starts ok. Problem was very intermittant for a month or so, but now is chronic after a long trip.

Answer
I'd primarily suspect a throttle position sensor.  But you should definitely go to a good driveability shop (or the dealer, especially if it's still under the 5/60 warranty) and have it diagnosed.  There are enough possibilities that it's unlikely I can give you a good answer.