truck-hauler for goods and people carriages on trains
i've noticed that sometimes traffic can be good on some days for trains, and not so good for transportation via the road surfaces, but sometimes, when trains are delayed, there is an opportunity for currently out-of-work trucks to deliver not only the goods that the trains carry, but also the carriages themselves to their destination.
for people, since it is possible for more than one carriage to be used dynamically, groups of people can move themselves into seperate carriages for their destination, and multiple trucks can automatically lift each carriage on to their assigned hauler, and take them as close as they can to their destination according to the grouping of people inside the carriages.
a high amount of automation would be required, but also an amount of common sense for truck-drivers for situations that need precision guidance. i would expect teams to be working for each carriage to ensure people get on to their destination carriage, and also for safety.
to ensure smooth transit between carriages and trucks, and also for the journey on road, trucks may need a higher priority on roads to ensure that public transport is faster than driving by car.
for areas where trains are stuck in a place that is not near a road, helicopters that are currently not on stand-by and are usable for transportation according to degrees of safety, could be used to transport the carriage to the nearest road where the truck can pick them up. i'm not so sure it should be placed on to the truck directly.
i'm not so sure this is a useless idea when it comes to transport times, especially if mathematical algorithms determine the shortest route and/or if the carriage should be transported via other means at all.
an _extremely_ high amount of hydraulics and safety measures would be required in each carriage itself to prevent tilting/rolling by computer-controlled safety systems with probability algorithms to help make the ride not only safer, but smoother.