Fifteen states require helmets for some riders, usually under age 16. So do over 50 cities and counties. We have the current list up on our Web server. About a third of the population of the U.S. lives in one of those states or cities. Enforcement is rare, and helmet acceptance is probably too low for compulsory laws to work well at present.
Prices are low, there are more color and style choices, and vents are always adequate.
Some have oversized vents and are very cool but have less foam in contact with your head, which could concentrate crash forces. Some have easier strap adjustments and rear stabilizers to improve fit. EPP can withstand multiple hits and recover after a crash. There are helmets now for downhill mountain bike racing with face protection. It became BHSI in 1989, in hopes of setting up our own lab test facility.