Some missions lower the friction of train tracks for non-trains for their entire duration.

If you load a save or start a new game, then the friction stays.

missions:

• Wrong Side of The Tracks (until killing every Vago) (30% friction)
• Snail Trail (40%)
• End Of The Line 3 (30%)

The strat is: Save before Snail Trail(I call it the "pre-ST save"). After Snail, save(post-ST save), load the pre-ST save and start the mission, then load the post-ST save and enjoy nice track friction until End of the Line.

The tracks on the way to Export might make it worth it. It is a must-use for non-LP ILs.

Powdinet quote: Not the most precise of tests because my driving is bad

For testing, you can use this speed-o-meter by Lighnat0r.

Source: http://gtaforums.com/topic/194990-gtasa-opcodes/page-21#entry4120462 Train tracks friction: opcode: 0A45 [set_rail_tracks_friction_to] Concerns vehicles driven over the rail tracks. setting is not overwritten by starting new game[or loading], default -1.0.