http://wiki.answers.com/Q/What_is_the_legal_size_motorcycle_allowed_on_california_freeway"
150cc
In Florida, a motorcycle must be at least 5 bhp to go on the freeway. The cops usually translate that to 150cc or better
50 cc , or above . u gotta get it licensed too.
In the state of California a "motorcycle" has a seat or saddle for the rider, and is designed to travel on not more than three wheels. A "motor-driven cycle" is a motorcycle with a 149cc or less engine size. Note: you may not operate a motor-driven cycle on the freeway. It is not advised to take anything less than a 250cc motorcycle on the freeway, even that could be dangerous. Besides a California Motorcycle License, Current Registration & License Plate, and of course Insurance; at minimum, your street-legal motorcycle must have:Tires with sufficient tread for safe operation.Headlight, taillight, brake light, and turn signals.Front and rear brakes.A horn and two mirrors.Hopefully you find this answer to be helpfull.
In California, its legally permitted to carry motorcycles without fenders as only trikes or four wheeler vehicles are bound to have fenders over them.
It depends on the state and their laws. I know that it is legal in California.
Yes it is Only Its Not Allowed in California
No moped type vehicle would be legal to drive on a freeway. The minimum speed on freeways is 45 mph. Moped type vehicles will not run that fast. A much better and safer alternative is a motorcycle like the Honda Rebel. It is a 250 cc motorcycle that will get over 50 mpg and is large enough to be safely driven on a freeway. It is a much safer vehicle than a moped with it's small wheels. Go to any motorcycle dealer and look at what they have.
A motorcycle cannot legally lane split in any state in the United States. However, in California, it is not often penalized.
It is physically possible, yes. I highly doubt it is legal though.
It is generally illegal to walk on the freeway as it is considered a restricted access road designed only for motor vehicles traveling at high speeds. Pedestrians are not allowed for safety reasons. If you need to walk along the freeway for an emergency, it's best to contact the authorities for assistance.
about the same speed as freeway traffic