It appears there are still artificial restrictions on certain Road Rules, as there had been in the past (such as Warren Ave. and Hans Way) where the game would discard times that Criterion deemed impossible to get through normal play (without exploiting a glitch).
I was attempting some bike nighttime Road Rules on Big Surf Island. I was trying to beat my old best time on Griffin Blvd. of 2.10. I reached 2.00, and other than seeing 2.00 on the top of the screen for about a 1/4, I got no acknowledgment ("New Road Rule Time" message) or scrolling ticker at the bottom showing the update.
I went back to Griffin Blvd. and the top time was still 2.10!
I tried several more times...got 2.00 again, 1.93, 1.92, even 1.82 at one point. None of these times would stick. This is very similar to what happened to me on Warren Ave. last year (which they eventually fixed with a patch).
I wasn't sure if it was a problem with the server not updating, or a deliberate "glass ceiling" put in by Criterion to restrict "invalid" times, so I went and beat a couple other Road Rules (both on and off Big Surf Island), and they all seemed to stick. Just my times on Griffin Blvd. would get thrown out.
I tried a few more times, and got slightly slower times. I got 2.08, and then I got the "New Road Rule Time" message and the ticker appeared at the bottom, just like I'd usually see when I beat a Road Rule. Went back to Griffin and it did in fact keep 2.08 at the top. I also tried again, got 2.03, and again got "New Road Rule Time" and the ticker. Went back to Griffin again, got 2.00, and it got thrown out (top time still showed 2.03).
So, Criterion's glass ceiling for Griffin Blvd. is somewhere in the range of 2.01 to 2.03. I don't know why that is, as it really isn't all that difficult to attain or beat 2.00 here. No shortcuts were involved, I stuck to the pavement the whole time. If they do another patch, then hopefully this is something they can take care of.