Fast travel in GTA IV

I often have to travel to missions on the other side of the city, and driving back and forth is getting tedious, even with my full-throttle, one-way-ignoring, traffic-light-ignoring driving style. I tried taking the subway but it's not really helping - just getting through the station takes a while, there are animations every time the subway enters or leaves a station, and worse of all, the subway actually travels in its intended route and can't take me anywhere else but the actual next stop. This may be realistic, but not really useful.

What other methods of fast-traveling are there, how can I use them and which is (generally) the best for traveling large distances? Does it depend on which island I'm on?

Solution 1:

If you set a marker on your map as your destination and hail a taxi cab you have the option to fast travel to that location once inside the cab. This feature does cost more than the regular cab trip would take but the difference isn't much.

The monetary difference doesn't matter at all if you have unlocked Roman's Cab Service feature by completing some of his missions. Just set a marker and call up the service for free fast travel.

Solution 2:

Adding to what Crag and Teo.sk said, take Roman's taxi. or, hail a cab and shoot once out of the window to get them to flee, so you do not have to pay. Most times this will alert the police and you may become wanted.