It depends on the timing of the other trams through the ride and whether you're in the first or second set of cars.
The vehicle speed is controlled entirely by the on-board CM. The lever at the driver's seat has multiple positions to set what speed the tram goes. The only time the ride itself stops the vehicle is when the car is approaching one of the show stop points (Load, Gangster/Bandit, Annubis, Oz, Finale). No matter what speed the tram is set for, it'll slow down and stop at its pre-determined location so that the battery charging plates line up.
Along the route there are red/green indicators at floor level that work just like a train signaling system. A driver is only supposed to continue if they have a green light. (I'm not sure if the car would e-stop like a monorail would if it runs through a red light, though) So if there's a delay at Load, the vehicles behind them can't leave the Finale room, the vehicles behind *them* can't leave Oz, and so forth. A major delay in any one spot quickly backs up the entire system. Since the block before Oz is the Casablanca scene, a tram can't leave Casablanca and proceed to Sorcerer's Apprentice until Oz is clear.
Now, there's also the matter of the front and rear trams going at different speeds through different parts of the attraction to allow for them to each see their Gangster/Bandit scenes by themselves, as well as reunite their tram drivers in the Annubis scene without the other tram seeing it. So the front tram will drive normal speed through to Bandit, while the rear tram goes a little slower to allow them to get ahead and then they see Gangster. After the Bandit tram reunites with their driver at Annubis, they cruise into Tarzan and then slow to a crawl through Tarzan and Casablanca to allow the Gangster tram to catch up. Meanwhile, the Gangster tram slows to a crawl in Alien until it's clear to leave Alien and proceed to Annubis. It then reunites with the front tram so that they're both cruising into Oz one right after the other. So if you're in the Bandit tram, you see a LOT of Tarzan and more of Casablanca than the Gangster tram does. If you're in Gangster you hear more Alien alarm horns.
It's a very complex choreographed system that's quite like a mechanical ballet, really.
-Rob