Speed racers, anti grav racers, sci-fi arcade racers, whatever you want to call them, could do without obstacles or weird mechanics. They are all about the speed and harnessing that incredible feeling from overwhelming velocity with tracks that accommodate it, not hinder it. These inconveniences directly inhibit your speed like anchors obstructing and annoying the hell out of the racer and their enjoyment to rocket through and tear up the tracks. Do you see this in any other racer? F1? No. Rally? No. Any other type of racer?? Nope, not unless it's something like TrackMania which is almost parkour in its player made tracks, it lends itself to that though with slight physics and supremely good handling designed for such tracks. I digress. Speed racers do not naturally lend themselves to this, they should invite you to experience extreme speeds. Throwing obstacles, narrow corners and "interesting" game play mechanics etc fundamentally confuse what speed racers are all about.
How much is it to ask that these games have deliberate and constructive design choices... I'm not saying don't experiment but I am saying don't make me reduce my speed to a slower pace like I've taken the scenic route and am seeing the sights or I am letting a cute little bunny across the course in a game where I am supposed to be traveling at incredibly high speeds. It's fine to have: alternate routes, avalanches, obfuscated far sight etc as long as it still facilitates my reflexes and the trajectory of the vehicle I am driving. Don't do it.