Google Maps Doesn't Know How Street Addresses Work

2 months ago 5

I was driving around Vernon, BC a few weeks ago and I asked Google Maps for directions to 3207 30th Ave. It confidently told me where to go but luckily my passenger noticed that it was actually directing me to 3207 34th Ave, four blocks north. Well that’s odd.

A few days later my cousin asked me (as the ex-Google still-nerd member of the family) if I could help with a Google Maps issue. The problem was that the address 138 W 6th Ave in Vancouver was being mapped at a location 2.4 km (that’s 1.5 miles or 123 furlongs) away from the actual location.

I could visualize the absurdity of where it maps the W 6th Ave address by asking Google Maps for directions between 136 W 6th Ave and 138 W 6th Ave. These addresses are adjacent in real life, but Google Maps gave me this:

That’s a long walk to get to the building next door.

There’s another fun way to visualize this bug. Search for “Clark & Page Casting Studios” in Google Maps. Then copy its address, shown in Google Maps, to the clipboard and ask for directions to Clark & Page Casting Studios from its address. This should be a zero-meter walk, but of course it isn’t. Instead it is, no surprise, a 2.4 km walk from Clark & Page Casting Studios to its address. Fun!

Or this silliness. If you navigate from “138 W 6th Ave Unit 1B” to “138 W 6th Ave #2b” then it is, you guessed it, a 2.4 km walk.

This error was pointed out to me because apparently aspiring actors kept going to the wrong place and being late for their auditions. These mistakes have real-world consequences.

There are more

Finding one error is curious, but two suggests a pattern. I started browsing Google Maps looking for addresses that seemed out of place. I quickly found three more.

1951 W 19th Ave in Vancouver is mapped at a 2.1 km walk from where its address should logically be. It should be in the 1900 block of W 19th Ave but is instead placed ten blocks away by Google Maps:

1355 W 17th Ave, North Vancouver is a particularly odd case because it is mapped as being in the wrong city (in Vancouver instead of North Vancouver), but on the right street (W 17th Ave) but in the wrong block (the 900 block instead of the 1300 block). As it turns out W 17th Ave doesn’t actually exist in North Vancouver. What is going on?

Typos? Street View?

The answer might be typos. 138 W 6th Ave is being mapped at the location where I would expect to find 1038 W 16th Ave located – a pair of single-digit errors. This requires that somebody/something made two errors when entering the address for 1038 W 16th Ave. The problem with this explanation is that 1038 W 16th Ave doesn’t exist – I cycled over there to check and the addresses go straight from 1020 to 1040.

3207 30th Ave in Vernon got a 30 changed to a 34. Maybe that was a typo?

1951 W 19th Ave is mapped where I would expect to find 951 W 19th Ave. This is another single-digit error. This one is less harmful because (again, I cycled over to check) there is no 1951 W 19th Ave, and 1951 and 951 W 19th Ave both map to roughly the same place. If you ask for directions from 951 to 1951 W 19th Ave (which should be ten blocks) you get these 0.0 km directions:

1355 W 17th Ave, North Vancouver is harder to explain. It was mapped adjacent to 979 W 17th Ave, Vancouver. This error severely stretches the definition of “typo” since nothing but the street name is correct (Vancouver and North Vancouver are different cities, separated by Vancouver Harbour).

I also noticed an anomaly in 5 Montcalm St, Vancouver. This address is in the 1300 block of Montcalm so the address makes no sense. I visited this location as well and the building address is actually 1131 W 16th Ave (the house is on a corner) and there is a five on one of the doors on the Montcalm side. Further creeping around the house revealed that there are five units inside the house – the five is a unit number, not a street number! Now I started wondering if a person or AI had seen the five on the door on Montcalm St and assumed that it was an address.

Internals guesswork

The fact that Google Maps can have these errors – that apparently the mapped location of addresses need have no relationship to the layout of the city’s streets – makes it clear that Google Maps has no concept of how street addresses work. There are many rules for how most addresses work in Vancouver but Google Maps appears to have no knowledge of these rules.

It appears that there is an address database somewhere – created by Google Maps, or the cities in BC, or perhaps from Street View data. Somehow that database seems to allow addresses to be mapped to parcels of land and when the address of a parcel of land is entered (by a human being or an AI bot) the database software happily accepts any address and maps it to the parcel, with no sanity checks to make sure it makes sense. Possibly sanity checks that are needed include:

Is the parcel in the geographical bounds of the city name entered?
Is the parcel in the vicinity of the road name entered?
Is the parcel in the correct hundred block for the road name entered?

These checks would detect all five of the errors that I found.

The hundred-block check only makes sense in some cities. In others it might be better to just do a comparison with nearby numbers, or perhaps skip that check completely. And there are enough weird addresses in the world that these checks probably just have to be a suggestion rather than a hard blocker.

Since there are apparently a lot of these bad addresses in the wild (my ability to find five errors in two cities this quickly suggests there must be many thousands) it seems that somebody needs to run a batch process over the database to find these errors – me scrolling through the map really doesn’t scale well.

While it seems clear that Google Maps uses an address database to map arbitrary addresses to parcels of land, it is also capable of guessing where an address would be if that address existed. That is, if I ask it to map the non-existent addresses 1953, 1955, 1957, 1959, and 1961 on W 19th Ave it places the address balloon in plausible locations, interpolating between 1947 and 1981 (the surrounding “real” addresses). This suggests that Google Maps has the knowledge and heuristics needed to correctly place 138 W 16th Ave, but this knowledge is then overridden by a database that contains errors. Fun!

Something new?

I talked to the business at 138 W 6th Ave and they said that these problems are new – starting around mid March. I don’t remember noticing this type of error before so it does seem like Google Maps might have just ingested a batch of bad data.

Attempted fixes

When I encountered the first two errors I confidently said that I’d use the Google Maps feedback tool to get the errors fixed. I’ve had good luck in the past with this. But this time my luck ran out.

I dutifully submitted feedback for “Wrong pin location or address”:

And I got an email the next day saying that my edit was accepted:

But it’s been 14 days and the address still maps incorrectly.

I had better luck with my edit to 3207 30th Ave that was accepted the same day. That fix actually went live sometime between April 17th and April 23rd. That is still nowhere near the promised 24-hour latency, but at least it showed up eventually. Maybe the 138 W 6th Ave edit will still go live?

Not all errors are equal

The first two errors that I found – 3207 30th Ave in Vernon and 138 W 6th Ave in Vancouver – are problematic because those addresses are real and Google Maps plots them incorrectly. This leads to people going to the wrong place.

The other errors are less important because they are non-existent addresses that are plotted in nonsensical places. This is mostly harmless.

Anybody else seeing this?

If you have noticed any similar anomalies then please share them in the comments.

If you work on Google Maps please reach out to me if you have any information that you can share. I’ve tried reaching out through some ex-coworker friends, but no luck so far.