There is the Beltline Trail (officially Kay Gardner Beltline Park) running parallel to Eglinton between the Allan Road and Chaplin Crescent. Bicyclists could bypass that section and could also use Castlefield to continue their trips. The Beltline Trail is missing a bridge over the Allen Road, which would continue it to at least Caledonia Road. If done properly they cold connect the Beltline as part of a bike lane/path network along Eglinton.
I moved this from the Eglinton thread. As for filling in the Allen, it looks like the window of opportunity has been missed, so we may want to look at other ways of alleviating the bottleneck at the bottom of Eglinton and giving an alternate route downtown.
Earlier I recall a concept to tunnel the Allen under Eglinton and then join up with Bathurst. Rocco Rossi also suggested continuing the tunnelling all the way to the Gardiner.
Maybe we could use the Key Gardiner Beltline trail. It may be too narrow, but I will assume it is at least the 10m that would be required. A SB off-ramp would be located north of Elm Ridge Dr. and would continue south to Aldburn Road. A similar on-ramp would be built from Aldburn Road to Elm Ridge Dr. and then onto the Allen. These would be connected to the beltway and continue to Bathurst Ave. and Chaplin Cres. I have an option with traffic signals and stop signs at the Allen, or with a "roundabout" using the 2 bridges. (I also have a SB to EB only option which is probably the worst of the group). The Beltline road would have no turns onto Oak Park Road - I suggest stop signs, but traffic lights may be needed because of the proximity to Elm Ridge Circle. At Bathurst, I would limit turns to EB to SB and NB to WB. It would join into Chaplin Cres. at a Y intersection.
Would the locals accept this - most certainly not, but it was a fun exercise to try to come up with a less expensive solution. After all, every decade the "extend Allen" argument gains traction so why not plan ahead.