I am driving up from Seattle WA to visit a friend in Vancouver BC next Thursday. I will probably arrive at the Canadian border around 7pm. Which is the best crossing point (i.e. fastest to get through)?
This time of year and that time of day just go up HWY 5. As you go up 5 (near Bellingham) they have overhead signs showing the wait time at the different crossings. This time of year 5 to 10 minutes is common for HWY 5. Summer and weekends much more.
This is also available, which shows real time, it also shows the wait at the nearby crossings.
http://www.wsdot.com/traffic/border/default.aspx
If it's busy, Sumas is usually your best bet.
Anything after 6 can get a bit dicey at the main ports, plan accordingly.

Tune your radio to 1130 AM before you reach Bellingham. Traffic every ten minutes on the 1's. It's a Vancouver station so you'll get the city on the Canadian side of the border as the crossing point. It will have to be a long wait at the truck crossing or Peace Arch to justify a trip to Sumas. Even a trip to Lynden takes a while to make up if you're going to Vancouver. Know the shortest routes to alternate crossings before heading out.
If you ever go earlier than that be advised that Hwy 99, what I5 turns into across the border, during rush hour becomes a nightmare northbound about twenty minutes from the border. There's a tunnel under the Frasier River that utilizes reversible lanes. Two GP lanes, and three merging lanes all squeeze into one lane through the tunnel. You don't want to get stuck in that mess.
There is usually little or no traffic at the Lynden POE around 7pm.
It's a straight shot down the Guide Meridian to I-5, should take about 20min.
Once you get to the POE.
Try to get to the lanes on the right.
The left ones will be blocked by those who can't read the big green open signs.
If traffic is bad, take the commercial lane to the Duty Free store and buy a candy bar.
Then exit and make a right turn back into the line.
