Table 1
Highways: 1999 Data (unless noted)

Public roads
" 46,567 miles of Interstate highways"
" 113,983 miles of other National Highway"
  System (NHS) roads
" 3,771,462 miles of non-NHS roads"
Vehicles and use
" 132 million cars, driven 1.6 trillion miles"
" 75 million light trucks, driven 0.9 trillion miles"
 7.8 million commercial trucks with 6 tires or
"  more and combination trucks, driven 0.2 trillion miles"
" 729,000 buses (all types), driven 7.7 billion miles"
" 4.2 million motorcycles, driven 10.6 billion miles"
Passenger and freight motor carriers
" 4,000 private motorcoach companies"
"  operating in the U.S. and Canada, 860 million passengers1"
" 511,000 interstate freight motor carriers2 (2000),"
  1.1 trillion ton-miles carried3
"1 American Bus Association, available at http://www.buses.org, as of Nov. 9, 2000."
"2 U.S. Department of Transportation, Federal Motor Carrier Safety Administration, Motor Carrier Management Safety Information System Report LS50B901 (Washington, DC: March 2000)."
"3 Eno Foundation, Inc., Transportation in America, 1999 (Washington, DC: 2000)."

"SOURCE: U.S. Department of Transportation, Federal Highway Administration, Highway Statistics 1999 (Washington, DC: 2000), tables HM-14 and HM-20."