The cycleways were mostly flat and there were cycle and pedestrian bridges, and underpasses which wouldn’t have looked out of place in the Netherlands at the time, mainly because they were modelled on Dutch infrastructure. Stevenage was compact and Claxton assumed the provision of 12ft wide cycle paths and 7ft wide footways – separated by grass strips as a minimum, and sometimes barriers, too – would encourage residents to cycle and walk everywhere. He had witnessed high usage of cycle tracks in the Netherlands and believed the same could be achieved in the UK.
Instead – to Claxton’s puzzlement, and eventual horror – residents of Stevenage chose to drive, not cycle, even for journeys of two miles or less.
There's a good writeup on Stevenage on Carlton Reid's site: http://www.roadswerenotbuiltforcars.com/stevenage/