Some good debates here. IMO, having the signal turn on is always good so that both drivers and passengers know where you are going next. Health and safety reasons.
you should've contested the ticket. if it's your first offense you should be able to get off. I don't know about where you live, but such type of "moving violation" increases our insurance rates for the next 6 years, so I definitely would've contested it, since it ends up costing wayyyy more than $100+ ps, I got a ticket once for "speeding" in the middle of peak traffic time at a section where someone had an accident. has the cop ever drove through the area during peak traffic? people are barely driving above 30 mph nvm speeding...I contested it. I think sometimes cops are just trying to get their quotas in IMHO.