Those taxes on weed don't look bad compared to what I think is the current equivalent product with even higher taxes - cigarettes - how is the situation different in your view?
There’s a much more robust black market already in place for marijuana than for cigarettes. Washington has all the same products and is right next door, and taxes at 3% [1]. Also at least in CA municipalities are adding their own taxes, so the distance you need to travel to enable black market arbitrage might not be much.
I've literally never heard of a cigarette-smuggling prosecution. I don't doubt that it happens, but it's small-time. Given the option, it seems that most people would rather pay a bit more than creep around like criminals to get their fix.
Here in Virgnia they have police set up on the north side of the Chesapeake Bay Bridge Tunnel. Alot of contraband moves to NYC via US Highway 13 North and the police are pretty good at spotting smugglers. Coming out of the tunnel you are in a pinch spot and they use this area for recon.
The tax on cigarettes in NYC is so high they smuggle from Virginia. Lot of guns move the same route and the NYC people keep complaining that we have weak enforcement.
1 - https://dor.wa.gov/sites/default/files/legacy/Docs/Reports/2...