Chris Boardman's report and recommendations for transforming Manchester. It spells out why, how and what needs to be done.
https://www.greatermanchester-ca.gov.uk/download/downloads/id/441/walking_and_cycling_report.pdf
UPDATE
That link no longer works.
https://www.greatermanchester-ca.gov.uk/info/20001/transport/165/cycling_and_walking/1