Big Rigs Beware Blaine/Surrey Crossing @ Vancouver/Seattle

OP is referring to the Pacific Highway border crossing. Aka "truck crossing" because that's where there are a lot of customs brokers and a different and larger areas for commercial trucks only. The Aldergrove crossing and Peace Arch are both good for RVs are are recommended if you are not familiar with the truck crossing. The Peace Arch and truck crossings are both at Blaine. The Peace Arch Canadian facility is fairly new and was built with RVs in mind.

The Pacific Hwy crossing is at it's worst if you have Nexus cards and are heading south into the US. There are 2 Nexus lanes, but usually only the most westward one is open and it is VERY VERY tight. We always use it this crossing because it's the closest to us. You MUST be lined up just right or you definitely will hit a steel post. Sometimes the CBA agents put the cones down in the worst possible spot and you will barely make it through. If you have Nexus cards and if you have a larger MH, a longer trailer or are nervous about clearance, use the regular lanes. On the way out going into the US, they have concrete barriers that you have to zig-zag through which are tight.

When it gets busy at the truck crossing like on weekends or holidays, when going north or south, and in the summer, it turns into a zoo. Some drivers cheat by going into the duty free stores in order to cut in way ahead of everyone else. Going south, there is also a side road that many use to cheat and get way ahead of the long lineup. The layout and roads on both sides of the border really needs a complete reconstruction at this crossing.

Trivia: Canada built a completely new facility at the crossing in time for Expo '86 in Vancouver so that it would give Canada the right image for visitors into Canada. Somebody really messed up on the structural design & construction. The floor in the main office area has settled a lot and is very wavy. You can really notice it at the main entry doors. The structure where the booths are has settled so much that the local municipal building authority will not permit the occupancy and use of the office area above the booths. I did engineering design work (not structural) on it in 84/85 and it's pretty sad to see what it looks like today...

FYI, there is RV "capacity" at most crossings
If you turn AM-1130 the lower-mainland station there give the border crossing times and ferry delays as part of the regular "traffic" reports.

We generally use the truck crossing, just slightly east of Blaine. Just follow the signs from I-5. It is labeled "truck crossing" but they take any vehicle.

I use to cross the Blaine/Surrey border station ten twelve times
a week in a semi, at time you could pull up and not wait ten
minutes to cross back into the U.S. other times it would be
a few hours. Would look over at the vehicle's with trailers
working their way thought those close booths and think I'm
glad I not doing that.

Tight going south too, there are a lot of scars on the barriers. It's not for show, a few have tried to blow through the crossing. We generally use the Aldergrove-Lynden crossing although it is currently under construction so a bit of a mess especially into the U.S.