Strava have analysed the data from all their users up until May 2015 and have created a “heat map” showing the most heavily used routes for cycling. This shows the current need for cyclists between Derby and Matlock to use the A6 as no suitable alternative routes are available.
Strava doesn’t represent all types of cyclists and can only show journeys actually made (so misses all those who would have made journeys if the Derwent Valley Cycleway was in place). However, it is a useful additional indicator of the need for an alternative to the A6.
The Strava heat map can be found here. Red shows the most heavily used cycle routes with yellow and green showing less usage.