You should also have looked at the Bay Area. SF added "exclusive" (painted) bus lanes to Mission St. in the downtown area decades ago. They have allegedly helped, though the change in travel time is miniscule and probably invisible to the riders. Then, the buses frequently have to stop and wait while somebody double-parks in the lane or is making a turn blocking it. Mixed flow traffic is certainly affected by loss of the transit lane. Of course, the Muni has an atrocious record for crime and grime, which affects it usefulness (you use it only if you have to).

GG Transit in the North Bay back in the 1980s when I used it, had a pretty good system going. Limited stop runs ran with mixed traffic in the outside lanes, making stops at bus pads at the interchanges; with auxiliary lanes between most of the interchanges, that allowed decent bus speeds and service to park/ride lots near many of the bus pads (and local buses on some of the cross streets). Commuter express buses used the HOV lanes (discontinuous at the time), and a reverse lane on the Waldo Grade in the afternoon. The reverse lane was a child of the '70s, and ended when the resulting lane reduction (the single bus lane took 2 lanes from the 4 on the freeway, one for the buses, and one "buffer" lane) for southbound mixed flow got so bad that traffic backed up to San Rafael. Plus, a couple of really bad wrecks happened when cars (including CHP in one case) got into the reverse lane; standing-room-packed buses heading downgrade on Waldo don't stop very fast. Buses stayed in the mixed flow after that, which didn't add more than a few minutes to the run, though northbound traffic was now messed up as expresses moved from the right to left lane between Sausalito and Marin City to enter the HOV lane. GGT also was pretty religious about cleaning and policing; very little crime even on the basic service.

I think part of why the HOV lanes worked (for both cars and buses) in the '80s was that most people more or less obeyed traffic laws at the time. The HOV lanes were for 2+ but you needed to be 3+ to cross the bridge free, so most were 3+. The routine 15-30mph over the speed limit that is observed today (when physically possible) was more like 5-10 back then. People mostly obeyed signs and stripes (the shoulder back then actually was the shoulder, not a 23103 lane for passing the dorks in stop & go traffic). Cell phones hadn't been invented yet (I had a TRS-80 Model 1 at home and used a 300 bps modem for timeshare access there and at work, with a TRS-80 Model 100 for hacking on memos and short papers while on the bus). So buses actually could use reverse and diamond lanes without (most of the time) having problems. The buses in the outside lanes with the bus pads could do that without other drivers jamming in on them all the time to save a car length and using the bus pads for an extra lane. None of that obtains any more, so the only practical alternative to even maintain (let alone improve) service was to get the transit completely off the road aka SMART.

Muni and Market Street, of course, were beginning to deteriorate toward the state they're in today...it was already difficult to get by the sit/lie/panhandlers on some parts of the Market Street sidewalk especially at subway station entrances, and stabbings were common enough in the mid-Market and Civic Center areas. Mission St. was still moderately safe, though. After 10 years of that commute, I was glad to be transferred to Fresno (20 minutes driving, 30 minutes bicycle, rather than 2+ bus hours).