The Statutes of Pennsylvania’s Title 75, Chapter 35, states that bicycles in Philadelphia must be equipped with a front light and a rear reflector. The front light should emit a bright, white light and the rear reflector should be red or amber.
As long as the front light can be seen for about 500 feet, it doesn’t matter if it’s a clear or flashing light. All rear reflectors should also be clearly visible from a distance of about 500 feet.
To increase safety even further, bicyclists should consider wearing reflective and/or bright colored clothing at nighttime. You could also place reflectors on your helmet for additional visibility. Note, these suggestions are not legal requirements in Philadelphia.
Pennsylvania law does require, however, all bicyclists to use audible signals when appropriate to warn pedestrians of their location. Ideally, bicycles should be equipped with a bell that can be heard from a distance of about 100 feet.
To read more about Pennsylvania’s laws concerning reflectors and lights, check out Chapter 35, § 3507 by clicking on this URL.