There are already too many, they're too big and add to deterioration of the nation's highways and bridges.
semi-trailer

Teamsters President Hoffa Says “NO” to Larger Trucks on America’s Highways
(via gas2.org)
Submitted by MaxMaxL on Fri, 2008-07-11 19:47. | Tags: transportation | Biodiesel | clean air | congress | environment | fuel | Hoffa | railroad industry | railroads | semi-trailer | semi-trailer trucks | Teamsters President Hoffa | Teamsters Union | trucking | trucking industry | trucks