The Slippery Slope of E-Bike Access

When I visited Bryce Canyon National Park recently, the shared paths were crowded with electric motorcycles. They say they are e-bikes: If they can rip uphill at 20 miles per hour without pedaling, I think of them as motorcycles.

E-bikes can be class 1, 2, or 3. Class 1 provides assistance when the pedals are turned. Class 2 has a throttle that can propel the bike without pedaling. Both have a top speed of 20 mph. Class 3 bikes, also pedal-assisted, have a maximum speed of 28 mph. Only class 1 and 3 are allowed in national parks.

Friends with e-bikes tell me they like them because the pedal as...