Is the navmesh system good for racing games?

HI everyone,
I would like to create an open world Racing game and I need to know if the navmesh system is a duable alternative compared to a classic spline system that everyone use in their games.

I noticed the navmesh itself is already heavy on the CPU, because it take at least 7ms… I don’t understand exactly why, but if it’s correct, I won’t be able to make any open world racing game with that.

Also I’m wondering if the dynamic navmesh system is fast enough to create a route where A.I. racing cars are able to avoid obstacles in time.

Let me know!
Regards,

Alessandro