They certainly command almighty slow-downs for all who dare traverse beyond snail's pace.
Either you come to a near stop or the fillings in your teeth fall out with the juddering aftermath of contact.
I find them excellent for sorting out the damping ability of new cars, though I don't think that is why so many are launched there (good food, lovely surroundings play a part too, I suspect).
The latest to use the facilities was Citroen when it recently unveiled its new C5 Aircross SUV - a rival for the Hyundai Tucson, Nissan Qashqai, Skoda Karoq, Peugeot 3008SUV, Ford Kuga among others.
One of the new car's perceived strengths is its 'floating carpet' suspension (Progressive Hydraulic Cushion), which they claim is easily best in its class to handle the rough and tumble of everyday Irish roads.
Now, seeing as there were a row of those sturdy speed ramps between me and the open road I thought it only right and fair that I should test Citroen's claim. So I belted into them, one after another at speeds I can't disclose for fear of being prosecuted. Put it this way: no other car I've driven at launch there would have patted the ramps out of their way in the manner of the Aircross. We were more than impressed. If you live or drive on poor, rutted roads, you could do wore than try this. It is exceptional. And it is standard on all the new-car versions.
But as most of us drive on better-quality roads for longer periods other factors simply must come into play for your decision to buy or not. Price, for one. The C5 Aircross starts at €26,495. That's a competitive kick-off because the level of standard (called Start) spec is high.
Yet few will buy that trim, they reckon. Nor will great numbers (10pc) go for Touch trim (costs an extra €1,500). But most (70pc) will plump for the Feel level (another €2,000) and 15pc for the range-topping Flair (€3,700 more again - see spec and prices far right.
This is a big car; at 4.5m a segment leader. It's tall too (1.7m). As a result, cabin space was excellent. The sliding individual rear seats give flexibility and contribute to a boot room total of 1,630 litres when flattened (the floor is virtually impediment free too). With all seats up, space can range from 580-litres to 720-litres depending on how far back or forward you have the rear-three seats.
I drove the 1.2 petrol 6spd manual and 1.5 diesel auto. While they expect diesel to comprise 70pc share I preferred the petrol; it was smoother and quieter.
And then there is the factory-fitted dash cam. This, they claim, is another first on a new car in Ireland. In the event of an accident, it records and automatically saves the 30 seconds before and 60 seconds after.
It has an integrated 16GB memory card to store photos and videos. Footage from a collision will automatically save to the device. They claim it is the only car here to have this technology as standard.
Such is the potential contribution it can make to safety, and the legal aftermath of an accident, that Citroen says it has verbal agreement from a leading insurance company to reduce premiums by 10pc for Aircross owners. Surely more companies will follow? If there is any real desire to cut premiums then here is an open-and-shut case to show faith.
As I said the car is among the biggest in the fast-expanding Compact SUV segment (4.5m long, 1.7m high, 2.1m wide). But it didn't feel unwieldy on a couple of necessarily brief runouts last week. Seating and visibility were good and there was a great sense of comfort.
Yes, Citroen has suffered an image problem for years but now it has a five-year unlimited mileage warranty (also standard) there must be some reassurance for potential buyers?
It will be interesting to see how this fares at a time when medium compact SUVs are in huge demand.
