I’m in the year 2080 in my game. I had to reduce the frequency of the lines to about 3-4 minutes to compete with the cars. Overall, they are quite slow, so if you use some 200km/h running trains and proper high-speed tracks they can beat the cars easily.
I also destroyed the shortest street connections between the cities and build longer ones (just to help them, so they don’t have to climb steep hills 😉 ). But I didn’t notice a significant increase.
But I noticed, that if you have a big city, the cars get stuck anyway because there are so many. So they balance themselves out somehow. In that case, I can really recommend to build bus-lanes, so your trams and busses don’t get stuck and get another advantage over cars. So in the end, cars are not that much of a problem.
