The Montague Street bridge is a light rail overpass, the lowest point of which is only three metres off the road. In the last six years, it has knocked the top off, knocked over, trapped and even exploded the canopies of 99 trucks and buses that were too tall to pass safely underneath.

The bridge's attitude is probably a mixture of embarrassment, emotional and physical bruising and the kind of overblown righteous attention-seeking outrage one sometimes encounters in restaurants when a waiter drops a coffee cup or brings a snack with gluten in it. After all, it's a bridge! It eats trucks and buses! It's still standing!

Still, nearly 100 times in six years. Surely the word gets around. Drivers of anything bigger than a HiAce should know to avoid the Montague Street bridge, shouldn't they? Or are they somehow bewitched?

It's possible. The red and white stripes on the bridge – meant to be a warning – could be confused for a candy cane or boiled lolly. In these obese sugar-craving times, it's possible that some truck drivers – often known to fill out a singlet with enthusiasm – are drawn on by the promise of a sweet treat.

Alternatively, the red and white stripes might suggest a barber shop and subconsciously drivers are literally giving their vehicles a haircut – most spectacularly in the case of a tour bus that lost a frightening chunk off the top. And there are memes out there that suggest the bridge is driven by bloodlust.

Okaaaay. It seems like you're blaming the bridge. What do the scientists have to say about the drivers?

Ian Glendon is associate professor in the School of Applied Psychology at Griffith University whose research interests include risk-taking, driver behaviour and traffic psychology. He says the "driver factor" is partly based on expectations.

"That if you keep your attention on the roadway, traffic, possible roadside hazards and so on, then you'll get along OK. A low bridge is an unusual hazard and so much less likely to be noticed than the more common varieties. And putting up large warning signs won't necessarily make a difference because often they are not seen, or read, or drivers consider that they are meant for others. This is known as the 'third-person effect' – the message is for others, but not for me."

Glendon suggests, too, that "various psychological mechanisms could be operating here. For example, a truck driver who regularly drives his car under the bridge might forget that today they happen to be driving a truck!"

The buses, however, are a puzzle, he says.

Yeah! You can't forget you're driving a bus.

Probably not. But if a bus driver comes into unfamiliar territory, then he or she can be overwhelmed by the demands of the alien environment. This is the suggestion of Dr Anjum Naweed, senior research fellow and traffic psychologist with the Appleton Institute for Behavioural Science at Central Queensland University.

"There is no way, with a bridge this low, that this is a regular route for bus drivers," Naweed says.  "In an unfamiliar area, the workload for a bus driver is suddenly very high. They're navigating for direction, not constraints. There are many distractions, perhaps in the moment of approach. And they've gone under many bridges before without a problem, so why should there be a problem now?"

Come on! What kind of distraction?

Professor Kristen Pammer, of the Australian National University's Research School of Psychology, wonders what was happening on top of the bridge when the collisions occurred. "If there was something actually on the bridge when the accidents occurred it would suggest that the driver's eye was drawn up to whatever is on the bridge, thus giving the illusion that it is higher than it is."

Hang on, this is too namby-pamby! Someone has to pay! Whose fault is it?

Short answer? The bridge.

Pammer, having studied photos from the Montague Street Hall of Shame, observes: "First of all, three metres is really low ... I mean really low. The minimum height for most overhead bridges is around 4.3 metres; there are a few less than this, but not many. Most bridges are well over 5 metres – all over Australia, not just Victoria. So, what does this mean? A driver has an expectation that there will be sufficient height, because there always is sufficient height. There is nothing in their driving mental repertoire – their 'mental set' for driving – that would let them to expect that they wouldn't fit. Yes ... there is a honking great sign hanging from the bridge saying that it is only three metres, but drivers don't look at signs. No really, they don't. There is research on this."

Her second observation is the killer. "As far as I can tell from the photo, the red and white warning stripes are actually placed a good metre above the bottom level of the bridge. That is, there is bridge, then the warning bunting, then more bridge. Why is this important? If the driver sees the warning bunting, they will expect that the bottom of the bridge will be at the bottom of the bunting – and not three-quarters of the way down. Similarly, warning strips on steps are placed at the edge of the tread, not halfway across the tread. If you expect the bottom of the bridge to be at the same level as the bottom of the bunting, then you will only see the bunting and not the extra metre of bridge ... and slam into the bridge."

Really?

That's what the photos suggest. But an inspection Saturday found the bunting - looking rather new and fresh - level with the lowest point. So obviously the bridge is once more playing with our minds.