Washington became the nation’s testing ground for bike-sharing programs with the 2008 introduction of SmartBike DC, a modest venture that began with 10 rental kiosks. Its successor, Capital Bikeshare, currently operates almost 500 docks. Three new programs — Mobike, LimeBike and Spin — don’t require any: A frame-mounted lock immobilizes the bicycle until a rider scans a bar code with a smartphone camera to activate it. When finished with a trip, the rider can leave the bike anywhere legal.

But critics worry most about beginner urban riders navigating the segmented nature of the city’s designated bicycle lanes: They begin and end seemingly at random, forcing cyclists to veer into four-lane roads stippled with potholes and urban grit. Buses and hurried automobile traffic push them into the right-most lane, where doors of parked cars can swing open unexpectedly, catapulting cyclists.

“I take the least intrusive route possible, and I still can’t prevent getting ‘doored,’ ” said Marcus Greenberg, a bicycle commuter of four years, lamenting that drivers curse him onto the sidewalks while pedestrians curse him onto the roads. “Without a bike lane, you’re the minority — everybody hates you. You flip over your handlebars, and the driver wants you to pay for the dent your head made in their Prius.”

One barrier to consistent bike lanes is what riders call “bikelash,” or local resistance to bicycle lane installation when it threatens parking availability. In 2015, when the city considered installing four blocks of bike lanes in eastern portions of downtown, nearby church congregants protested in such large numbers that a Department of Transportation meeting was dispersed due to a violation of the fire code.

Another barrier is the prioritization of “levels of service,” an engineering measurement for the rate at which a motor vehicle can be moved through an urban intersection to minimize congestion. Such was the case on Grant Circle in northwest Washington, where a recent plan to install a protected bike lane was scratched because it would have narrowed the motor vehicle path to one lane from two.