Frequent runners and riders on Chicago's lakefront trail know that at two spots its smooth and continuous pavement comes to an abrupt end.
On the north end, just past Hollywood Avenue, the trail diverts riders onto Ardmore Avenue and sends them west for two blocks before funneling them north again on Kenmore Avenue.
For riders heading to Evanston, the two miles that follow are dangerous and piecemeal.
Kenmore, a street pocked with potholes and speed bumps, heads north until it dead-ends into the campus of Loyola University of Chicago.
There the bike lane ends. Bike riders or runners can head back toward the lake on Loyola's campus and ride or run the sidewalk that continues along the lakefront.
At the end of Loyola's campus, however, that sidewalk ends forcing cyclists and joggers west again toward Sheridan Road.
Sheridan is an extremely dangerous road to ride, and though it is lined with sidewalks, bikes are strictly not allowed.
Signs all along Sheridan Road warn adult cyclists that riding on the sidewalk can land them a $50 fine, get them arrested or lead to their bikes being temporarily disabled.
The northern gap, long a residential area, is heavily populated by lakefront condos, some of whom enjoy private beaches and aren't interested in a public path passing through. Some properties wall off "their" part of the beach making it hard for even people just walking on the beach to make it far without having to turn around.