Studies comparing motorway vs bike lane costs
https://activelivingresearch.org/sites/activelivingresearch.org/files/Dill_Bicycle_Facility_Cost_June2013.pdf

For example, the City of Portland calculated that the city’s
entire bicycle network, consisting of over 300 miles of bikeways would cost $60 million to replace (2008 dollars), whereas the same investment would yield just one mile of a four-lane urban freeway.


...bicycle lanes can often be added to streets as part of planned maintenance or re-striping projects at a cost of $1 - $5 per foot (excluding right of way acquisition and engineering costs). Bicycle boulevards... generally cost between $9.50 and $27.20 per foot.

Assume values are US Dollars from 2008.  Portland is fairly close to Canada, and the 300:1 ratio is mentioned, fortunately the units cancel out.
The only niggle I can see is that a 4 lane freeway has four lanes, whereas the bike lane's width is not stated.  So it could be 75:1 ratio, or 1200:1 if the boulevard could take 16 bikes side by side.