This route goes from west McKinney to Allen Premium Outlets, a huge shopping area. It uses the Cottonwood Creek Trail. Like all my routes, it avoids road traffic as much as possible. Here's Allen's official route map. Unfortunately, Allen's trail network is currently an ugly mess, but upon closer inspection there are many usable routes through Allen once you combine the official trails with the many numerous sidewalks.
The first part of the route leaves McKinney and crosses under the Sam Rayburn tollway. Around half the route is on trails, the rest is on sidewalks. It may be a bit intimidating at first for a pedestrian/e-biker to cross underneath the tollway, but once you figure out the patterns of lights at this intersection it's easy and quite safe.
The Allen part is around half-trail, half sidewalk. As you get closer to 75 the amount of traffic turning to/from Stacey Rd. dramatically increases, so it pays to slow down, pay attention, and take it easy on this part. (This area of Allen as a huge amount of traffic, so even for drivers it can be a real pain to get around here.)
This route also goes past Wal-Mart in McKinney, and a movie theater in Allen. Overall, this route is easy and takes around 25 minutes in decent weather.