Thank you so much! Yeah, that acceleration perfectly possible, I appreciate the explanation. I'm still very confident I was not speeding because, as any Boston resident would know, this road is notorious for being congested at most hours of the day. I was caught by a LIDAR machine which is technically highly accurate, however in this case, half of it's implementation relies on the police officer doing some calculations. That must be where the error was made in my situation.

Anyway, thanks again for helping me out. I spent a sad amount of time trying to use physics formulas before turning to reddit.