I'm basing street car speed on operating conditions elsewhere in this country, specifically Portland. Their streetcar is scheduled
at 6.5 mph though maintaining that speed, despite greater amenities than local buses, has proven difficult
. The 18 bus is scheduled to run between 18 and 20 minutes from Lake to 3rd street. That works out to 7.5 - 8.3 mph.
The Portland streetcar's runtime is comparable to other buses
in the urban core of Portland; most figures exaggerate the difference by comparing its speed to that of all buses in the system, including ones in less-congested areas with wider blocks (and commuter express buses). MAX through downtown is only slightly faster, mostly because it has wider station spacing.
If you can get a paper copy of Appendix C - Run Time Methodology from the Nicollet Streetcar Alternatives Analysis read the laughable run time projections [ie bus maneuverability and not needing a totally clear platform to open vehicle doors doesn't outweigh the ability of rail to consistently approach a station. (Holy Lord mixing streetcars and buses on Nicollet Mall will be disastrous) ] and then give it a more appropriate use if you're out of toilet paper. (the AA is also online: http://www.minneapolismn.gov/nicollet-c ... S1Q-071591
I too am worried about the implications of mixed buses and streetcars on Nicollet Mall, but I think you're underplaying the time-savings implications of level boarding. I take the 18(/17/11) every day through downtown at least three or four times, and I can say from constant experience that buses lose tons of time on nearly every run when they need to kneel (or, heaven forbid, extend the ramp) to accommodate the elderly and people with strollers.
(The other night, for example, I was on a NB 18 that missed two lights at 9th kneeling, extending the ramp, and boarding a lady with a stroller. She got off at 7th.)
What are the advantages of streetcar over enhanced bus? It's certainly not construction costs, operating costs, construction impacts or transit travel time. The arguments I read generally focus on real estate development, street calming and place making. Significant real estate development is happening right now without the streetcar, so that argument doesn't hold water. However, the city is eager to divert tax dollars that would have existed without the streetcar to its funding. In my experience Nicollet is a pretty dang friendly pedestrian street despite the crummy state of the sidewalks. I find it's really easy to jay walk midblock or cross at the unsignaled intersections, unlike Lydale Avenue S. Place making kind of goes along with the first two and it's worth noting that 26th and Nicollet intersection has really taken off in the last two years despite horrific 26th Street bisecting the intersection.
All the advantages you mention are important. There's also significantly higher capacity, which is important, especially given rail bias (someone earlier worried that the streetcars would be full all the time, given how full the 18 is, but this wouldn't have the quite significant numbers coming from the many 18 branches south of Lake).
But yes, of course real estate development is a critical thing. You're correct that on some portions of the route, there has been (and will likely continue to be) significant real estate development. However, that's not true in all portions. The stretch from 15th to 24th has large numbers of vacant lots and underutilized or shuttered buildings, with even more located a block in either direction (eg. two corners of 15th, the western stretch north of 94 to 15th, the parking lots and vacant lots on 18th, the Family Dollar complex, both north corners of Nicollet and 22nd, etc.) In Stevens Square and Whittier, aside from the two buildings at Nicollet and Franklin and the building housing Bad Waitress, there's been very little large development in years. Even if the Streetcar won't likely produce a Rose Quarter-style construction boom, it's hard to argue that the area doesn't need whatever help it can get.