High speed rail has revolutionised intercity travel, but it remains an expensive form of transport. Buses are a cheaper alternative but take forever.
To fill that intermediate gap in the market, I suggest high speed bus. The vehicle is essentially a stretch limo except it's also stretched sideways
to accommodate a 4 abreast seating arrangement, like on conventional buses. But because it is as low as a car and has a more powerful engine it is capable of cruising at a speed of 160 km/h (100 mph). It has a door next to each seat row to allow the 40 passengers to board sideways, and luggage is stored in a oversized trunk in the back.
Compared to normal buses which travel at a speed of 100 km/h (65 mph), this bus will achieve a time saving of 30-40%, while still costing less than rail travel. For example, the journey time from London to Manchester could be reduced from 4:30 to 2:45, which is almost as fast as the train and much faster than flying.
In countries where there is a speed limit on motorways the bus would be piloted by a driver trained to high standards, making an exemption possible.