What is your average heart rate over a 40-45 mile ride at a moderate average speed of 18-20 mph on a rolling road course?
For what you describe - it could be anywhere from 95 to 130.
The unfortunate truth - cycling conditions vary so widely that comparable HR data is worthless.
However, compiling years and years of your own training data
can become one of the most valuable training tools to date. The more you know,
the more accurately you can plan your training.