Just found these (en.wikipedia.org/wiki/Rubber-ty…) advantages/disadvantages of rubber tyres vs metal rails (ht @WouterHermans) and learned of metro driving on tyres but guided by rails. I'm starting to get convinced the days of the train on metal rails are over. 
Recently I've done some projects with @GeertKloppenbu1 and had twitter conversations with @MLiebreich that started me thinking again.
The aforementioned wikipedia entry gave me an epiphany: I completely overlooked that we only have steel rails for historic and outdated reasons.
The aforementioned wikipedia entry gave me an epiphany: I completely overlooked that we only have steel rails for historic and outdated reasons.
The most important reason is that it can give guidance.
So you can have long vehicles that drive flawlessly along a predetermined route.
But driving straight on your a road that's kept free for just your vehicle is child's play for modern automated driving systems.
So you can have long vehicles that drive flawlessly along a predetermined route.
But driving straight on your a road that's kept free for just your vehicle is child's play for modern automated driving systems.
Against that no longer existing advantage are severe disadvantages:
Rail is louder and more bumpy.
Braking is harder, leading to long distances between trains.
Most importantly, vehicles can only drive over the rails which limits where they can pick you up or drop you off.
Rail is louder and more bumpy.
Braking is harder, leading to long distances between trains.
Most importantly, vehicles can only drive over the rails which limits where they can pick you up or drop you off.
It would be much more logical to have a 'rail like' system over concrete where a passenger train is basically a platoon of busses driving closely together and a freight train is a platoon of trucks driving closely together. Of course you can mix them and allow smaller vehicles.
(If we really think out of the box: concrete roads and matching tires could have a rolling resistance not too dissimilar to steel tracks and you could even include the coils for wireless power transfer when pouring the pieces of roads in the factory.)
'Road trains' would be able to transport about the same amount of people and goods as trains but would be as flexible as a system using separate busses, trucks and cars that is able to use all flat surfaces.
So the efficiency of a train with the flexibility of a road.
So the efficiency of a train with the flexibility of a road.
Implementation could be gradual. E.g. with one lane on one highway only usable by self driving vehicles forming road trains.
We could even give these lanes electric overhead lines so the electric trucks and busses can recharge while using them.
We could even give these lanes electric overhead lines so the electric trucks and busses can recharge while using them.
My biggest question: can we combat particulate matter from tires? Does anybody know of any research that could shed light on this? E.g. by directly collecting it from the road, by enlarging particle size, or by making it biodegradable. @carlovdweijer @M_Steinbuch @FlorisTriest
Anyway: thanks for reading and it seems to me the competition between road and rail will be even more interesting and complex than I thought, with road trains competing with regular cars and trains.
(Usual disclaimer: don't forget walking and biking in the city.)
(Usual disclaimer: don't forget walking and biking in the city.)
