Apple and Google received panicked letters from a Scottish council after their GPS kept sending vehicles down a flight of steps

We’ve all had that moment where we realize we need to be wary of GPS. You track down a highly recommended restaurant on Google Maps only to find it moved locations a couple of weeks ago. Or you take an Apple Maps–approved shortcut straight into a dead end. On rare occasions, you might even find yourself unwittingly barreling down a flight of Edinburgh steps.

That last one might sound like hyperbole, but it’s an issue a surprising number of drivers in the capital of Scotland found themselves in over the past couple of months.

The issue became widespread enough that the City of Edinburgh Council was forced to get in touch with Apple and Google to ask the tech giants to update their GPS, short for “global positioning system,” after out-of-date maps left multiple drivers stranded in a stairway beside a pub.

Drivers get a surprise

The council installed steps on the city’s Greenside Lane and blocked the road off from traffic as part of street design guidance that sought to make the street similar to others in the city, including those linking to the famous Royal Mile.

However, those updates weren’t reflected in Apple Maps or Google Maps, which continued to direct drivers down the path.

Reports began to emerge last month that the issue was leading to cars getting stuck on the steps beside the Theatre Royal Bar, with the Metro reporting that a Toyota Prius and SUV were known victims of the mix-up.

Amused residents have taken to social media to publicize a trend that was at risk of becoming endemic, and also appears to have affected heavy-duty transit vans and delivery vehicles.

One of those unfortunate people, an unnamed delivery driver, told BBC Scotland: “I was just following the satnav [satellite-based navigation]. I always remember I used to come down this way. I followed it and just got stuck.

“I had no idea there was a step there; I used to come down this way. I am a bit embarrassed about it.”

Letters to Google and Apple

In a paper published last week, the council said it had been made aware the change had led vehicles to careen into the steps.

A representative for the City of Edinburgh told Fortune that Google had updated its GPS to reflect that Greenside Lane was no longer suitable for cars, while Apple had been asked to make a correction.

Fortune has approached Apple for comment.

An experiment carried out by Fortune using both Google Maps and Apple Maps shows drivers are no longer directed down Greenside Lane. A representative for Google confirmed to Fortune that it had updated its map as soon as it was made aware of the change.

While it waited to confirm the maps had been updated, the council installed a temporary barrier to prevent further accidents from happening.

Councillor Scott Arthur, the city’s transport and environment committee convener, said: “The footpath in this area is incredibly busy, so these incidents are really concerning.

“While we would expect drivers to use common sense in a situation like this, we are going to install temporary barriers this week to prevent it happening again.

“Satnav is an incredibly useful tool, but it’s no substitute for common sense. Cars and trucks don’t go down steps.”

Be wary of GPS

GPS, or as Brits call it, “satnav,” has improved by leaps and bounds since it was first popularized among consumers as an in-car attachment.

According to Google, the maps are updated constantly or, to quote its maps group: “literally, every second of every day!” The group appears to use a “Swiss cheese model” of risk management, where layered defenses minimize the possibility of a notable error occurring.

“We’re constantly collecting new information about the world, whether from satellite imagery and Street View cars, or Google Maps users and local business owners, and using that information to update the map.”

But smaller updates, including the placement of a few steps, are much harder for satellites to pick up on a map, and updates may slip through the net.

On this occasion, it seems Google’s and Apple’s various avenues for updating maps fell short in Edinburgh.

The accidents in Scotland’s capital, which didn’t lead to any reported injuries, offer a sobering reminder of the limits of modern-day technology, particularly as drivers begin to embrace autonomous driving.

And the incident serves as a reminder: Next time you’re directed down a side street, make sure to double-check what’s really there.

This story was originally featured on Fortune.com