Apparently Fort Worth has some of the best MUPs because I rarely have issues like a lot of people mention. First of all, the busiest MUP and the section closest to me goes through a very populated and mid- to upscale area, so security is pretty good. The MUP is fairly busy in that part of town also, which also helps security. Too crowded? Rarely. We are lucky in that when they built the MUP along the river, they started with service roads along the banks (the entire river was rechanneled after flooding in the 1940s, so the Army Corps of Engineers built stone service roads as part of the project). So every part of the MUP is at least crushed limestone that is easily wide enough for heavy vehicles. In many areas though a dedicated, paved path was added alongside the original service road. This creates a two-tiered system, with slower bicycle traffic, pedestrians, joggers, dog walkers, etc., sticking to the stone path (which at this point is fine and compacted) and faster traffic (i.e., bicycles) on the paved portion. There are a lot of criss-crosses between the two paths, so there are places to get around knots. It's not perfect and a lot of pedestrians can be found on the paved portion, but there's still generally plenty of room, so I'm rarely nervous about collisions. Sometimes I do have to slow down for traffic, but in general it is a safe, effective transportation route for bikes. Also the MUP follows the river under bridges, so there are no actual road crossings.

Here you can see the paved and stone sections running alongside each other


Here the stone path is off to the right of the paved path