[adinobro]

That isn't true. You have multiple tracks for a reason. Generally, you have three separate trains on the same tracks and a sidetrack that goes into the cities or two tracks that split before the city and merge after the city.

1. Direct - They have the least stops and are the fastest. They don't go into towns. They go around them. 2. Express - They only stop at the largest towns. 3. Regular - They are the slowest and stop at every town.

You then use timing to make sure that they don't crash. The slow train will generally stop on the track and wait while the direct overtakes it (you don't want them both moving at the same time).

This isn't new. It's be around for 100 of years.

[saalweachter]

This is about routes, not lines or spacing.

If you have three cities on a perfectly straight line, you can run your high-speed trains as above.

If the city in the middle is not on a straight line path between the two end cities, now your train tracks need to curve to connect the three. If you make the curve a large enough, smooth enough curve, it won't hurt your maximum speed much, but when you're talking "1000 km/hr" ... and in any case, you're also adding miles to your route, and if you make your route 20% longer to weave from city to city along the way, you are also make it 20% slower.