Boston’s slowest MBTA buses are getting slower, while bus bunching finally starts to ease

Average speeds on the MBTA’s slowest bus routes dipped again, with the 10 slowest lines averaging just 6.42 mph.

At the same time, one chronic rider complaint eased somewhat, as buses on the worst routes were less likely to bunch up and arrive together instead of being spaced along the route.

Here’s what to know

TransitMatters’ third annual Pokey/Schleppie report found that the system’s 10 slowest MBTA bus routes averaged 6.42 mph, down from 6.52 mph a year earlier. Across the 10 routes with the most bunching, that share fell from 15.8% to 13.9%, according to Commonwealth Beacon.

The group framed the 52-page study as its annual “awards for bus inefficiency.”…