If you've played any Mario Kart, you'll know the horrible feeling of having driven phenomenally, being in first place, and then hearing the horrifying sound of an approaching blue shell. Boom. Just like that, the cluster has caught up with you and you're left to struggle at the back of the pack, attacked from both behind and the front.
This is undeniably part of the appeal of Mario Kart, but also sometimes unnecessarily unfair. And that's something Sega wants to avoid with Sonic Racing: Crossworlds. In an interview with GamesRadar, Sonic Team chief and producer Takashi Iizuka explains that they started with the racing instead so the game could stand on its own without items:
"They wanted to make sure the racing itself without any items was fair and fun. The dev team really took things down to the base level, and wanted to have that fun, competitive racing mechanic."
Only with that in place did the team start adding items and conducting "a lot of playtests". But a lot seems to have been dropped, because balance is important and Iizuka explains that "anything that was very stressful for players, anything that always allowed people to come back from behind and win all the time needed to be removed from the concept."
So, in a nutshell, it seems that we shouldn't expect much in terms of Bullet Bill and blue shells. The idea is that the driver who has raced best should generally finish first, and if you want to overtake, it's a matter of practicing rather than relying on items.