How much extra time should I reserve to enter the US from Canada with the Windsor-Detroit Tunnel Bus as a European VWP citizen?

You can check how long the delay is online at the Canadian Border Services Border Wait Times page. This page is updated once an hour. I see at the moment that "Detroit and Canada Tunnel" is listed as No delay which the page explains means less than 10 minutes for traffic into Canada. The US has an equivalent page for traffic into the USA which lists "Detroit Windsor Tunnel" as no delay as well. (This is the time to reach the point of interaction with a border person: you then need to add some time for actually dealing with that person. However, as Affable Geek says, the way they have the cars all flowing smoothly like that is by keeping that dealing time to an absolute minimum.)

You could check this page a few times at the time of day you intend to cross, and on the same day of the week, to gain an overall "feel" for a given crossing. You could also check it again when you are going to travel to decide if you need to take an earlier bus. Then just to be on the safe side, have a Plan B for if you do miss that Detroit bus, though it seems to me that you won't.

The Windsor Tunnel is highly efficient - as an American, it consisted of flashing my passport, and 30 second look, and a move on. My experiences both in Detroit and Buffalo (Niagara Falls) are such that if the stop is more than a 10 minute delay, there was something really strange going on that day. Road crossings with Canada are easy, low-key affairs. It's as memorable as a toolbooth.

As a non-American citizen, it might take a little bit longer, but I doubt it would be more than a few minutes - assuming everything is in order, and you don't look like a druggie or a terrorist. Remember - you are sharing the same road as a bunch of depressed auto workers who have just returned from gambling in Windsor. You are an item to be processed, not a threat.

Guards at the border are interested in protecting the homeland to be sure, but they also know there is an unwritten need to keep traffic flowing. The multiple lanes make it feel like a tool booth more than a border control - and overall, it works very, very well.

If still in doubt, consult with the sages:

Transit Windsor 3700 North Service Road East Windsor, Ontario Canada N8W 5X2

Phone: For detailed inquires, call 519-944-4111. For general inquiries, call 311. Fax: 519-944-5121 Email: tw@city.windsor.on.ca

Why not just book the entire trip from the Greyhound.ca/com site, including the border crossing itself?

Doing this with the same company gives you a guarantee of through-transportation. They understand, and schedule around, the length of time it takes to enter the USA at the border; however if you were unfortunately detained for far longer than usual, either they would keep your transfer bus at the station longer, or you would automatically be booked on the next bus - no need to worry about "what if I can't make the bus if I take too long at customs?".

Here's my personal experience a few years back, visiting Toronto twice via Greyhound, starting from the mountainous state of Colorado. Both trips I re-entered the US via Detroit; the first trip I entered Canada via Niagara.

If you are booked on a schedule that includes a border crossing, you will have the same bus all the way into Detroit the entire way way from Toronto, and at Detroit you will have some period of waiting before your connecting route.

My return back to the US did take a bit longer than the stop at customs into Canada. Detroit totalled maybe 30-45 minutes vs 10-15 for Niagara and Windsor's respective customs stops. Both times in Detroit we had to get off the bus for about half an hour while they questioned a number of people at length, and then everyone had their baggage searched.

Please note that my trips were taken in 2010 and 2011, the situation may have changed (hopefully for the better) since then.