Question You must dim your high beam lights when within: Answers 100 feet of an oncoming vehicle. 250 feet of an oncoming vehicle. 300 feet of an oncoming vehicle. 500 feet of an oncoming vehicle. Explanation You must dim your high beams whenever you are within 500 feet of an oncoming vehicle. Pass your DMV Written Test with flying colors Take me to the cheat sheet Washington This questions appears in the following tests: Washington Practice Test 19 Washington Practice Test 5