For drivers trying to get a look at oncoming traffic, a transit shelter with a full-sized ad posted on it makes a better door than a window.

One of the big revenue generators for Astral Out of Home’s deal to provide the city with street furniture is transit shelter advertising. Shelters offer the largest blank space on which to post ads that can be seen by passing drivers.

The 20-year street furniture contract with Astral is good for both sides; the city gets a nice slice of the ad revenue, plus thousands of transit shelters and other street furniture pieces, while Astral gets an even bigger slice of the dough.

But in its zeal to provide customers with the most advantageous positioning of ads, Astral can lose sight of the bigger picture: Balancing the interests of advertisers with an imperative to not block sight lines for drivers.

Al Citron sent us a note saying a new transit shelter was installed earlier this year at the southwest corner of Drewry Ave. and Gardenia Ct., near Bathurst St. and Finch Ave.

“The full-length ad on the eastern wall of the bus shelter makes it impossible to see eastbound traffic, which is very heavy during rush hour, unless you drive out into the traffic lane,” said Citron.

“I’ve called the city and they had me call the bus shelter people. They said that they referred the complaint to those in charge and that’s all that they can do.

“Meanwhile, it’s been over a month now and it’s very dangerous to exit our street,” he said, adding he fears that “a serious collision will occur.”

I went there on Wednesday, when afternoon rush-hour traffic was starting to increase, and saw that the full-sized ad on the wall of the shelter obscured oncoming traffic until it was close to Gardenia.

The only way to get a good look at eastbound traffic was to inch out into the street until the shelter wasn’t a sight impediment. But Drewry is a busy street at peak periods, when inching out at the wrong time could get the front of a car clipped.

STATUS: We asked the city’s street furniture division if it could persuade Astral to remove the ad on the east wall of the shelter, and keep it clear so drivers can see what’s coming. The street furniture boss has just been moved to a new job, so Eric Holmes, who deals with media for transportation services, emailed to say he will direct our request to someone else who can deal with it.