You hit on a little understood sidelight of suburban transit planning. Some roadway layouts would require literally traveling unproductive miles to get to a place where it is acceptable as a turnaround. In the same metro area another suburb designs convenience center intersections so that they have a road around the back side of the center and apartments across the street. A bus route clicks right in there and the operator will like their break.There are of course other factors that have lead to the downgrade or failure to upgrade in some transit services. The bus service in my city is for the most part way better than it was when I was growing up, but there are geographic limitations to some routes. Others have been shortened to meet safety guidelines, after a fatality several years ago transit busses no longer can back up at the end of a route and must now go around a block to get back onto the route. The concept of a block is daunting in some of the suburban route ends. Also the further towards the northern outskirts you get in my city, the fewer east/west routes that are suitable for bus travel there are. So the map tends to look like fingers off of a central palm, which ends up making the trip to a central transfer point work against anyone trying to take the bus between neighborhoods.
While none of that is inherently racist, it has the effect of making the bus unappealing to the suburban neighborhoods which have the least minorities and more appealing to the urban ones which have developed into minority neighborhoods as time went on.
The racial and/or income issues involved with transportation are much more complex than discussed here. Gentrification results in new issues as the gentrifiers tend to faithfully cram onto weekday peak service for all the good reasons and then drive out to shop or ski on the weekends. Based on ridership the remaining longer term residents eventually lose some or even all weekend and night service. Some community leaders are fixated on getting better service with their community and will point fingers at lightly used suburban locals, but guess who is among the riders on the suburban locals? THEIR constituents riding to where the jobs are.
Now, as suburbs age and interest rates remain low the "doughnut ring" suburbs are attracting families who would have been confined to the inner cities before. The doughnut ring suburbs -- often platted in the 1920's/30's -- are usually easier to access with buses than the mile-square 1970's/80's plats but often have no sidewalks. Some areas within cities like Denver and Portland that annexed doughnut ring suburbs also have no sidewalks. Some have token sidewalks that are "narrow-gauge" -- too narrow for a wheelchair or to get around an open car door.
Trying to juggle things like these made service planning constantly interesting.
More on these issues in an old article that I wrote:
The Terror Tax