RCTgo

Yeah, when you click on the track piece all of the options for track type should light up (chain, block and trim brake, drive tires, etc.), click trim brake to switch the track section over and then if you click the right-hand tab it'll take you to advanced options for that track segment. In there you'll be able to alter the rate of deceleration and the target speed, I'd suggest making the target speed between 15 and 20 mph, and then slightly sloping the out-n'-back section of track downwards (something like a 3-5 degree decline should keep the cars moving at that speed the whole time they're in that track section). The same method can be repeated for the other similar sections of track.

If that doesn't properly slow them enough you can always mess with the rate of deceleration, unfortunately I'm not really sure what the target figure should be for that value.