The petition is dealing with safe passing distances Penfold, not mandatory use of cycle lanes.
I hope it achieves consultation stage.
The current paper on Cycling and Walking Investment Strategy aims to
Double cycling, where cycling activity is measured as the estimated total number of bicycle stages made each year, from 0.8 billion stages in 2013 to 1.6 billion stages in 2025;
Reverse the decline in walking activity, measured as the total number of walking stages per person per year;
 Reduce the rate of cyclists killed or seriously injured on England’s roads, measured as the number of fatalities and serious injuries per billion miles cycled, each year;
ï‚· Increase the percentage of children aged 5 to 10 that usually walk to school.
www.gov.uk/government/uploads/system/uploads/attachment_data/file/512895/cycling-and-walking-investment-strategy.pdf
Anything that makes cycling on the roads safer is welcomed and something that requires experts to consult on safe passing distance can only be a good thing.