It appears the repair costs that you mentioned is for the car's bumper that you rear ended at a stop light. If this is correct, you would not be using your collision coverage to cover the other person's vehicle but instead your property damage liability coverage which does not typically come with a deductible.

Property damage liability coverage reimburses the other party for their vehicle's damages in an accident which you are responsible for. Collision coverage covers damages to your own car, no matter who was at fault and does come with a deducible of your choosing.

So the $500 deductible would be for the collision coverage that covers any damage done to your vehicle at the time of this accident. If you do not have any damage, you will not need to file a claim for your vehicle or pay this deductible.

Under the property damage liability coverage there should be no deductible but because of paying out a claim on your behalf, the insurance company might raise your rates at your next renewal period. With this information you can decide if you want to pay out of pocket or have claims go through your insurance company for the damages.