Midtown Urbanist
Superstar
I don't know what you are talking about in terms of "walking distance"- If routed under the 404, it could have a stop at Woodbine and Steeles. There must be more than 10,000 jobs (IBM, BMO, Extendicare, etc) within walking distance.
- A stop around Esna Park/John Street would improve transit for 000's more workers
- A final stop at Highway 7 would connect with Viva and provide reasonably quick access to Markham City Centre, Richmond Hill City Centre
These are 1.2km walks if you are lucky, often longer, through windswept, harrowing, high-traffic, industrial areas and parking lots. Nobody is doing that during the winter. Even exiting these office buildings to reach your car in the adjacent parking lot is a massive hastle to overcome on windy days.
As much as I like the idea of connecting these employment lands (if it were feasible) I fear that sending it up Woodbine is problematic. It is too far west to serve Markham City Centre (which will be well served by GO-RER) and it is too far east to serve Richmond Hill and Langstaff Gateway (which is currently not serviced well by rapid transit). Personally, I would send the Relief Line to the latter direction instead of or in addition to Yonge North.