I can't find anything on bike lanes shared with tramways/streetcar lanes, but I thought for sure I had seen that online somewhere. But there is a lot of stuff online about bus/bike shared lanes, here's a video from Paris:
http://www.streetfilms.org/mobilien/
Tucson apparently even has some of these (if Tucson can be this foreword thinking, so can we. ).
I imagine it could work just as well for Trams/Streetcars as it does for buses. Bikers sharing a dedicated lane with only a bus or tram means they're only dealing with professional drivers. Additionally those public transit vehicles are by their nature coming at a lesser frequency than all the cars on the road, making things smooth sailing for cyclists.
This of course saves space where you're trying to retrofit a project on an existing road with buildings, as there may not be room for a dedicate 4-6 foot bike lane.
I had assumed all 6 lanes on McDowell Rd were the standard 12' width that most arterial street lanes in Phoenix seem to be. Google Distance Calc is telling me that may be wrong, but there's a fair margin of error when using that. Without actually being in Phoenix I can't know for sure how wide the lanes are, but there should still be room for streetcars/trams & auto traffic.
Additionally, if the City were to ever undertake a project like Streetcar from 19th Ave to the 51 I imagine part of it would be dramatically reducing parking requirements for adjacent business. With theoretically more people accessing the area by bike and transit, the huge overstock of surface parking would become even more silly.
Many of these business have large surface lots as well as diagonal parking between the sidewalk and the businesses (think My Florist) which would also have to go. You don't want people backing or having to make weird maneuvers onto busy arterial streets. Entrances for parking should be limited to specific, standard driveways going into surface lots & garages. This would free up space in the fronts of buildings for more plantings or moving the sidewalks back from the street and adding a planter strip or patio area's, et cetera.
Smallish garages (with retail/office facing McDowell obviously) could be built every 1/2 mile or so on some of the surface lots to make up for any unacceptable loss in parking. Of course these could also serve as Park and Ride's for a hopefully rejuvenated "Miracle Mile" for those coming from further afield. Park your car in a garages once, ride the streetcar up and down McDowell all day and transfer to LRT if you want to too.
It should also be noted that some of the planters facing McDowell are probably a bit too huge. There was originally on street diagonal parking along the Miracle Mile that those planters replaced. Some of them are up to 20' deep and mostly just full of gravel and dying shrubs. Some of that space could perhaps be repurposed to make more room for auto and bus/tram/bikeways.
At the very least if a Streetcar were too pricey or too progressive for Phoenix a shared bike/bus lane going each way (with 2 lanes of traffic going each way). It would dramatically increase the reliability of the buses. It would make the area safer for bikers and it would be a good place to prove a concept that could in the future be used elsewhere in the City. If McDowell did begin to redevelop and we saw more 4-8 story mixed use structures along that 4 mile or so stretch, then perhaps a Streetcar could be put in place later.
It just frustrates me that in large part due to poor infrastructure by the City that McDowell Rd is such a shitburg. The vast majority of the residents of Encanto, Willo, north Roosevelt, Los Olivos, Ashland Place, Alvarado and FQ Story aren't hurting cash wise. Add to that the fact that Coronado continues to gentrify, Calle 16 might become something interesting (though more working class) and it stands to reason that McDowell has a boatload of potential as a walkable, urban street full of shops, cafe's, etc.
Every other God damned City our size has this sort of shit, there's zero reason we shouldn't besides the fact that we can't stop pissing on our own feet.