I would hope so, unless you ride your trainer in the back of a truck going down the highway.

Seriously though, unless you have some way to monitor how hard you are working on the trainer (heart rate / power) you'll really have no idea of how hard you're working. 183bpm on the road or rollers feels pretty much the same to me: painful.

One of the hardest things to come to grips with as a competitive cyclist is that the numbers on your speedometer don't matter. Ever. (Ok maybe a little if you're in a time trial with a goal). In past years I was obsessed with average speed, if a solo ride came in below 20mph, I'd be bummed. I was always shooting for a higher average. This year, I've been purely focused on interval training with heart rate and haven't had a solo ride average out much over 19mph. However, people now curse under their breath when I show up for the Thursday night hammerfest. Winning the town line sprint by 20yds is much more fun than looking at speeds >20mph in my training log.

Everybody new to cycling will completely ignore this advice and continue to focus on average speed, that's fine.. just realize that at some point, you will stop getting faster.