As someone who has used that trail numerous times to get from my house in Vaughan to NYCC, I can say it is fairly reasonable as a transport corridor. As you say, it would really benefit from better link into the Centre of NYCC, and that is exactly what I said we should build. Doris and Beecroft would be great as paired one-ways, with Beecroft being southbound and Doris being northbound. That way there would be space freed up for bike paths along either Yonge or both Beecroft and Doris.
I can certainly see the logic in having Doris northbound and Beecroft southbound,.... the simpler right turns at Yonge between 401 and Sheppard,.... basically (after getting off Hwy 401) northbound Yonge traffic would make a right turn onto eastbound Avondale or Anndale (when that extension is open next year) then a left onto Tradewind/Doris (when they become connected),.. likewise, southbound Beecroft traffic at Poyntz and Yonge would make a simple right turn onto southbound Yonge. This avoids problematic left turn at Yonge which would lead to more traffic congestion.
The problem is practicality,.... if you walk around NYCC, you'll notice that most of the high density condos are to the east of Yonge (more offices are on west side of Yonge in NYCC),... between Yonge and Doris Ave,... and in morning rush hour, many of these condo dwellers want to head south to get on Hwy 401. But Doris Ave would be northbound! Thus, they'll have to drive north on Doris a bit to Greenfield/Elmhurst or Elmwood/NorthYorkBlvd or Empress/ParkHome or Church/Churchhill or Finch, etc,... to drive another half km to get to the southbound Beecroft,... but halfway there, they come across southbound Yonge,... hmmmm,... tempting! Why drive another 250m west to Beecroft to travel a few 100m south on Beecroft when eventually you'll need to backtrack another 250m east to get back onto Yonge?!?!? Compound this with the office traffic coming into NYCC,... off Hwy 401 to northbound Yonge then northbound Doris and since most offices in NYCC are on the west side they'll also need to go westward along Greenfield/Elmhurst or Elmwood/NorthYorkBlvd or Empress/ParkHome or Church/Churchhill or Finch. Thus in AM peak time, both local condo dwellers AND office traffic are going westward along these small streets! Who's going eastbound? It's heavy unbalanced traffic,.... this heavy westbound traffic will need longer green signal light at Yonge,... and futher delay Yonge traffic.
The one way street idea would work a bit better in the after noon rush hour since more of the northbound Yonge traffic are diverted to northbound Doris to the condos on the east side,.... and traffic from the office on the west side of Yonge will do south on Beecroft towards Yonge then Hwy 401. But the AM peak time traffic is much more critcal than PM peak time traffic,... since people have to get to work on time in the AM,.... PM rush hour traffic is more spread out.
It's very tough to make a oneway street network work efficiently. Hamilton downtown is basically all oneway streets,... but its downtown retail is basically dead since nobody stops to shop. Westbound Richmond and Eastbound Adelaide in downtown Toronto work well as one way streets because they run the length of the downtown core and have direct access to the DVP. In addition, there's no major artery between them - King and Queen Streets are clogged with streetcars. These are issues with making Beecroft and Doris oneway streets,... they don't have direct connection to Hwy 401 and Yonge Street is right between them,... promoting even more traffic onto Yonge Street,... the NYCC Service Ring Roads were suposed to get local traffic off Yonge Street!
So would you like us to demolish the buildings beside them to widen the street? And I've been downtown and I can say they work better than the streets around NYCC despite being barely half their width.
Yes,... demolish those properties! Do you think houses and buildings last forever? I live in NYCC for over 20 years,... half the post war bungalows in my neighbourhood has already been demolished for McMansions or condos,... and these bungalows are only about 50 years old. The houses in downtown are typically 100-150 years old,...
Of course, since these are private properties, the city can't go in and blindly demolish them,.... but eventually these properties will want to rebuild to a bigger store or condo or whatever,... then they'll need city permits,... the city will insist that the first 10 feet or so (from city property line to front of lot) be given to the city! It'll happen property by property,... it might take 50-100 years before the city get all the property required to widen the street by 10 feet, the width of one lane of traffic,.... but it'll happen eventually. That's already being done on Sheppard between Leslie and Yonge,... same concept will happen along Eglinton.