For buses, they are the number one enemy. For motorists, the vehicles they most hate, and for pedestrians, about the most likely to raise the blood pressure.
Vans are the bedrock of the moving economy, the great enabler of online shopping - but also the most loathed traffic on the roads.
Broach the subject with bus operators and it’s clear there’s a sense of huge frustration.
Buses are in crisis in parts of Scotland, beset with slower speeds from congestion and declining passenger numbers that have followed from that.
A central part of the problem is vans - and other vehicles - parked in bus stops.
It causes widespread havoc, from passengers being delayed, long queues of traffic building up on busy streets, and pedestrians unable to cross the road safely.
Some operators tell me they have even been forced to change bus routes because of parking in bus stops, or parked vehicles preventing buses even making it along some streets.
I’m also told of the millions of pounds spent by Scottish bus firms on “low floor” access, so that those in wheelchairs, with prams and pushchairs, and people with reduced mobility, can more easily board and alight.
All that is wasted if budding passengers can’t reach the bus that is sitting marooned in the middle of the road, rather than its expensive doors aligned properly with the kerb.
When I’ve contacted the van companies involved, they have told me their drivers have received training on responsible parking.
But there’s clearly an attitude among some such drivers that bus stops are fair game - they are simply viewed as empty parking spaces, never mind the dozens of people who are often held up because of the thoughtless actions of the few who misuse the area.
The mindset appears to be related to van drivers’ perceived status in the traffic social order, thinking of themselves as more important - like some car drivers - than others on the road, especially buses and their passengers, cyclists and pedestrians.
However, it’s even worse when the miscreants are vans from local authority firms, such as those for building and maintenance work on council properties.
When such vehicles occupy disabled parking spaces, zigzag lines outside schools, and “Keep Clear” areas on the corners of streets designated for safe children’s play - as I have seen in recent weeks - they are setting an appalling example to other drivers.
On top of that, it is also hugely ironic, because not only are councils - their ultimate employers - responsible for parking enforcement in many areas, their other important roles include promoting road safety, such as around our schools.
The outlook, unfortunately, is bleak. Council funding continues to be squeezed, limiting the available resources to increase patrols, who effectively have to catch offenders in the act.
Police Scotland is grappling with funding cuts, which is likely to curb their ability to help tackle the problem.
Perhaps bus stop cameras will be needed. From the large sums generated by errant motorists driving in bus lanes, they could quickly pay for themselves, especially in areas with the scarcest parking and greatest temptation for selfish drivers of vans and other vehicles.
Or maybe bus lane camera income should be ring fenced for such measures.