Questions about training vehicles equipped with two steering wheels.

With two brakes and two gas pedals! I Remember some old movie had the hero going to driving school, and using one of those cars.

Recently, it looks like they are not used much, even in driving schools. Why?
As I read a little on the matter, it looks like safety was a good reason to use double steering. But how did that work? Does the instructor’s wheel have more power? How does the instructor in that setup override the gas pedal of the student?
Another related question is: do car makers still make them? Or do the double stirring and other tools have to be added later?

Well, when I went to driving school I was taught on a car like that.

The instructors wheel just works simultaniously with the drivers wheel, the assumption being that students don’t actually want to send their car into a ditch - when the instructor turns his/her wheel, it turns the driver wheel also - sometimes a little jog is all the driver needs to correct a mis-turn.

The break works just like the drivers break - it overrides the gas - next time you’re in your car, push the break down as hard as you can, and then hit the gas - assuming your breaks are working, you won’t go anywhere - the instructor break is just like that.

As to when they’re made, I always assumed it was after-market modifications, but I could be wrong.

When I was in driver’s ed, the car had an extra break pedal, but thats it. Some mail cars around here have 2 steering wheels so that the mail carrier can put mail into the boxes along the right side of the road.

But if the student turns left and the instructor turns right, then what happens? Does the instructor’s steering wheel override the student’s? Or does the car follow the directions of whoever puts the most muscle power into the turn?

The one time I was in a car like that, the instructor’s steering wheel was mounted via some brackets to the underside of the dash and attached to the studen’t wheel by way of a bicycle chain-type contraption. So it’s just a mechanical thing.

Most airplanes have dual controls. They are mechanically linked so that two people can’t give different inputs. Dual steering wheels in a training vehicle are basically the same. I suppose the instructor could have a suicidal student that manhandles his wheel straight into the side of a building buts that is just a risk of the profession :slight_smile:

I don’t know if manufacturers ever made these, but they most certainly do not now. After all, what would be annual take rate for such a vehicle? Packaging redundant controls for a few dozen vehicles per year (per model per manufacturer) would cost astronomically more than any potential profit. Cars are complex and hard to build with just a single set of controls.

The two steering wheels can’t turn in different directions; the system behaves the same as if both people have their hands on the same steering wheel, i.e. whoever is applying more force is going to determine which way both steering wheels turn.

I actually inspected how these are done, when I was involved with driver training. And someone above is right, it’s an aftermarket add-on, where the trainers steering wheel is linked to the real one by a chain drive, and the brake pedal is linked to the real one with mechanical levers and springs. Nothing fancy, nothing designed in by the manufacturer. That would be insanely expensive to do, because the manufacturer would only be able to sell a relative few dual control vehicles every year, and the sales would be going to businesses that don’t have high profit margins (driving instructors are not paid quite as much as Trump level CEO’s).

Bumped a 14 year old zombie for that?
FWIW, my drivers ed car (circa 1998) had only an additional brake pedal. The instructor used it once, because I was coasting through an imaginary pedestrian crossing area before a stop sign.

I remember the instructor telling a story about how that exact car had been nearly totalled by a student who was turning onto a narrow bridge with concrete barriers on each side. She wasn’t fully in control, and he was trying desperately to reach her steering wheel. In his words, she was quite overweight and “filled the area between her and the steering wheel, and I couldn’t get my hands on it.” They hit the concrete barrier, but the car was new enough that the damage was worth fixing.

This car that holds the current coast-to-coast record in the US uses dual controls. Made easy since the Infiniti has no physical steering mechanism, it is a pure steer by wire design! Porsche 911s also use this approach in some models.

Dennis

When I was in Driver’s Ed, the teacher had a brake pedal on their side, and that was it.

The cars in my driver’s ed class also just had the brake pedal. Fun to slam down on it when someone was practicing stopping at a stop sign or whatever on our closed course that we used for practice :slight_smile:

For the answers to all these questions, just look at any standard cabover garbage truck
they have the same set up.

Zombie go sleep now

For the record, Balthisar didn’t bump this thread. A spammer did, and then got squished.

And I don’t think that, in most cars, the brake pedal actually overrides the gas pedal. It’s just stronger. If you slam down both, the engine will try to race, but the brakes will be holding it in place (I don’t actually recommend this, of course, since I’m sure it puts a lot of wear on both).

Yeah, thanks for that. It’s, uh, weird that I didn’t notice that. I’m usually one of the first with the zombie comments.