Close to the edge of London, there's a certain roundabout with a series of large shops surrounding it. At some point in the past, one of the shops put up a fairly innocuous advertisement that happened to feature an attractive girl without an overabundance of clothing. The sign was removed about a month later after traffic incidents on that roundabout increased by about 75%.
The same thing happened with a Janet Jackson billboard sometime in the 1990s. If memory serves, it might have also been in London...
It was claimed that the Hello Boysadvert◊ for Wonderbra would cause car accidents.
Played straight and subverted at the 2009 G20 summit. Presidents Obama and Sarkozy were on one side of the frame, and an attractive Brazilian intern on the other. Due to a trick of the still frame, it looked for all the world like the two were ogling the girl's backside. Video of the event shows that Obama was actually watching someone else's footing (they were on a staircase); Sarkozy... not so much.
Evidence for this trope in real life can be found here as well.
Their explanation of "evolutionary programming" is a lot less likely than there just being a limited blood supply.
Taichung police has ordered the city's scantily-clad betel nut saleswomen to dress more conservatively to help reduce car accidents, it was reported. Under the new dress code, women peddling spicy chewing betel nuts at roadside stands are barred from revealing their bodies in sexy transparent clothes or soliciting business on the streets, the local TVBS station reported. Don't put on any dissipated poses such as dancing outside the sales booths, a policeman said while promoting the new dress code... Taichung police consider the so-called betel nut beauties a likely cause of traffic accidents in the central city as drivers are often diverted by saleswomen in flashy revealing clothes, the report said.
Barrister Alex McBride in his non-fiction book Defending the Guilty tells how he was assigned to handle a bail application for a junkie who was pretending to be insane. He was too inexperienced to realise he was being conned, until the junkie's stream of gibberish was interrupted by the sight of an attractive blonde lawyer bending over to pick up her pen, whereupon the junkie exclaimed: "Gawd, can I have her defending me?"
Dress reformers in the 19th c. introduced the "Bloomer costume" which consisted of a full knee length skirt over baggy trousers tied at the ankle — not exactly revealing. Yet one leading feminist abandoned the costume because whenever she addressed an audience of men they were so distracted by her ankles that they didn't hear a word she said.
Commercial airlines invented the Sexy Stewardess trope because when their original (male) flight attendants gave warnings about emergency procedures, it scared the passengers so badly that some would insist on being let off on the airstrip. Replacing their stewards with good-looking women invoked this trope, giving their (mostly male) clientele something to think about besides plane-crash statistics. Supposedly the decision to make interface voices (like the recorded warnings on a plane, for instance) female in general follows similar logic.
That's not really a case of looks; more of not appearing manly by demanding to be taken off the plane. After all, if the stewardess was traveling by air and apparently not afraid. Of course the more pretty a girl was, the more you'd want to appear macho and fearless.
It seems every other summer some city in Florida bans bikini-ed girls from performing any commercial (or charity even) activity on the road side. Often citing traffic accident increases as the reason.
Phryne(NSFW) was a courtesan in Ancient Greece, known for being inhumanly pretty. When she was accused of blasphemy, one of her lovers defended her - and won the jury by stripping her naked in front of them. Shortly thereafter, they all unanimously decided she was not guilty.
As noted elsewhere, though, this was a case of Grecians having a solid belief that Beauty Equals Goodness - she was attractive, therefore she had to be good!