The State of Texas will register two categories of slow moving motor vehicles; Golf Carts and Neighborhood Electric Vehicles.  Texas defines a NEV in the following way:

A “neighborhood electric vehicle” is a motor vehicle that:

• is originally manufactured to meet, and meets, the equipment requirements and safety standards established for “low speed vehicles” in Federal Motor Vehicle Safety Standard 500 (49 C.F.R. §571.500),
• has four wheels,
• does not have to be powered by electricity (other power sources, such as gasoline, are acceptable),
• is a slow-moving vehicle, being able to attain a speed of more than 20 miles per hour but not more than 25 miles per hour, and
• is not a golf cart (designed by the manufacturer primarily for transporting persons on a golf course).

See more on this here : http://www.txdot.gov/txdot_library/publications/government/doing_business/bulletins/2009/001-09.htm

Here is a picture of a typical NEV:

Note the presence of a NHTSA compliant roof, seat belts, and all the seats are forward facing.

The state of Texas has the following to say about golf carts:

A vehicle is classified as a golf cart if it:

• has no less than three wheels,
• has a normal maximum speed of between 15-25 mph, and
• is manufactured primarily for operation on golf courses.

A golf cart may be driven without registration:

• within two miles of a golf course,
• on a public or private beach,
• inside city-designated areas of a master planned community, if a city or county ordinance permits such usage, and
  during daylight hours.

A registered golf cart may be operated on public streets if:

• it is manufactured with a maximum speed of 25 mph,
• displays a proper “Slow Moving” vehicle emblem,
• and is insured.

See more on this here: http://www.txdot.gov/drivers_vehicles/golf_carts.htm

Here is a picture of a golf cart typical of the ones currently operating in Downtown Austin.

Note the roof is made up of a fiberglass sunshade and a thin metal uprights.  Also note that there are no seat belts and the third row of seats faces backwards.  If this type of golf cart were hit by a car from behind the rear passenger’s legs may be crushed.

If the City of Austin wants to promote the long term use of electric vehicles it should require these vehicles to comply with federal safety standards.  Because golf carts are are not required to comply with federal safety standards, manufactures do not build them to the same safety requirements that Neighborhood Electric Vehicles must comply with.  Golf carts  are built to be used off roads, on golf courses.  NEV’s are built to be used on the road.

Below are some video clip examples of golf carts rolling over and tossing their passengers: