What’s up with the 13 ton maximum on Route 29 here?
https://goo.gl/maps/kQL7gNSXLAmSD5aZ9
The restriction is for the tunnel south of Cass Street. The truck route is to continue on I-295 to I-195.
When the tunnel was about to open, there was concern among residents that there'd be a big increase in truck traffic, so in natural fashion, NJDOT banned them. NJ 29 is mostly a commuter route anyway, so the many commuters were fine with that too.
One of the purposes of the tunnel was to hide traffic, including truck traffic, from the neighborhoods. Shortly before the tunnel opened, NJDOT did an about face and prohibited trucks from using the tunnel.
Personally, I think there's something a little more sinister involved...such as they didn't want trucks rumbling thru the tunnel, vibrating and cracking the concrete.
Some truckers with knowledge of the area will go thru, knowing the chances of a Trooper being nearby to stop them is rare. (I guess Trenton police could stop them also, but based on observations they largely let the NJSP handle the truck issue.) There's the occasional trucker not familiar with the area that finds themself confused as they'll see the "No Trucks over 13 Tons" signs, especially after the point of no return. They'll creep up real slow to the tunnel, hoping they can squeeze under (the tunnel is built 15 or 16 feet high, so they'll easily fit in). Of course, they're now delaying everyone behind them as they creep forward.
The truck route on 295 and 1 doesn't really exist anymore - the signage was removed long ago. Instead, they permit trucks to use Cass Street, even though there's signage saying trucks shouldn't be using Cass Street. It's not enforced. Cass Street is heavily residential with a few corner businesses. And a prison. Not really the road to be sending truckers, but that's how everything panned out.