the heaviest passenger vehicles on the road, all too heavy to cross a 3 ton bridge

1. Chevrolet Silverado 2500HD 4x4 Crew Cab High Country: 7,552 lbs

2. Ram 2500 Power Wagon Laramie 4x4: 7,324 lbs
3. Nissan Titan XD Crew Cab S 4x2: 6,709 lbs
4. Ford F-250 Super Duty Super Cab SWB 4x2: 6,230 lbs
5. Lincoln Navigator L 4x4: 6,069 lbs
6. Cadillac Escalade ESV 4WD: 6,040 lbs
7. Lexus LX 570: 6,000 lbs
8. Toyota Sequoia Platinum 4x4: 6,000 lbs
9. Rolls-Royce Phantom Drophead Coupe: 5,995 lbs
10. Land Rover LR4: 5,941 lbs
11. Bentley Mulsanne Speed: 5,919 lbs
12. Porsche Cayenne S E-Hybrid: 5,809 lbs

If you're doing the math, and thinking... well those aren't 3 tons with the last 4... now add the adult human and a tank of gas, and bingo! Over 6 thousand pounds/3 tons.

http://www.thedrive.com/new-cars/1720/8-cars-that-legally-cant-cross-the-brooklyn-bridge
http://www.barking-moonbat.com/index.php/weblog/comments-editor/17893/
http://swpare.blogspot.com/2014_10_01_archive.html

FWIW, the USA just allocated 50 billion dollars (or some such idiotic amount to get to mars with astronauts.) to a stupid waste of money notion instead of fixing the bridges in the USA

Above, the I 35 bridge which went SLAM for no externally caused reason. No earthquake, hurricane, or tornado.

It simply was not maintained and prevented from rusting away because politicians had to get rich and pay back campaign contributors for getting elected in other contract ways. It's known as "deferred maintenance"

They screwed the ordinary people that commute to work every day in cars over that bridge instead of being responsible to their oath of office.  13 dead, 145 injured.

And this was the Cyrus Street Viaduct, Oakland Ca. 42 people killed when it succumbed to an earthquake, it hadn't been retrofitted to handle, plus, it was built on landfill.

http://www.thedrive.com/travel/5419/when-bridges-fail-people-die?xid=hl