Computerized directions can be completely wrong

This is a cautionary tale about depending on getting directions from a web site.
This example is using Google Maps, but I suspect such problems lie with all the systems.

I know Montreal pretty well, so when this person looking lost on the street showed me the Google Map directions I was astonished to see that the directions were completely in the opposite direction to the desired destination.
It claimed to provide walking directions from Metro Station Place-d'Armes to The Quays Skating Rink, Ville-Marie, Montreal. Now The Quays are in Old Montreal - which is South of the metro.

Google Maps gets that right when you just search for quays skating rink in Montreal. But it somehow gets confused when Get Directions is clicked for that place, with a starting point of Station Place-d'Armes. Instead of telling the user to head south towards the river the directions point northwards into the city!
There is no skating rink in that part of the town at all. And the Quays are quite famous landmarks in Montreal. So this was a fail on the part of Google Maps. Not a big deal actually keeping in mind that it is easy to use Google Maps itself to get a second opinion regarding directions to verify them.

To back up, here are the directions from the Google printout I saw:

1. Head northeast on Avenue Viger O toward Rue Saint-Urbain.
This is actually confusing. The Metro is right on that street, so Ouest or Est is not very helpful. Secondly, people in Montreal are used to calling streets going northeast-southwest as just east-west.
2. Turn left on Rue Saint Urbain.
3. Turn right on Boul Rene-Levesque O S
4. Turn left on Rue Clark - 60m.
Arrive: The Quays Skating Rink, Ville Marie, QC (NOT!)
This is where things are totally wrong. Rene-Levesque is in the wrong direction entirely from The Quays. And that part of Rue Clark is quite desolate - there are no shops or businesses there so there is no one on that part of that street.

The correct directions are quite simple. Instead of left on Rue Saint Urbain, they should have said go right (south) on Urbain until you hit the water. Turn left on de la commune and you'll see the quays and skating rink right there.

I tried this search myself the next day - picture is shown below and it clearly shows incorrect walking directions!
Wrong directions
Same results were seen at both google.ca and google.com, though there were some very slight UI differences.

While this mistake is not good, Google Maps is actually quite helpful and it itself can be used to get a second opinion and thus get correct directions.

In this example, searching for quays skating rink shows the correct location next to the St Lawrence River in Old Montreal. This can be confirmed as the right address by using Google Search to visit the web page for the skating rink. From that Google Maps page (showing the correct location for the Quays Skating Rink), clicking on Get Directions is where things go wrong. The destination is listed as Ville-Marie, Montreal, QC (The Quays Skating Rink). Most likely the walking directions are to the center of the Ville-Marie arrondissement and it ignored the specific point The Quays which are at one end of Ville-Marie. Directions by car are wrong too, in the same way. Clicking around on other place markers on Maps lists an alternate destination that omits the Ville-Marie and just says Montreal, QC (The Quays Skating Rink). Those directions are correct. So it is the Ville=Marie that is throwing things off, even though it is actually more accurate and smaller area than using all of Montreal.

So the lesson here is to be warned - be very careful of using directions from automated systems. They may not be ready for real world use yet. Use Google Maps itself to get a second opinion on Google Maps. And that will get you to your destination safe and sound.