Busy downtown 2-way streets are often the most difficult streets for cities to reconfigure and retrofit. Many of these streets suffer from double parking and loading conflicts, have heavy turn volumes, and offer insufficient accommodations for bicyclists and pedestrians. Retrofit constrained 2-way streets using lane diets and conventional bike lanes or add cycle tracks that decrease the overall width and offer a higher quality bicycle facility.
Existing Conditions
The above illustration depicts a constrained 2-way street in a central business district. While many downtown streets were converted to 1-way operations, many were not, resulting in streets that are heavily congested by buses, bikes, people, and cars. Especially in older cities, these streets may be a main route for multiple modes.
1On major bus routes, curbside bus stops may be undermined by double-parked vehicles and heavy rush-hour traffic. These obstructions hurt the reliability and on-time performance of transit vehicles.
A lack of organization and striping can invite unintended uses and double-parking.
Freight vehicles double-parking at peak hours create weaving conflicts and safety hazards for motorists and bicyclists.
This street in Seattle uses a planted central median to create a street geared towards slower speeds.
Recommendations
The street illustrated above depicts a 50-foot roadway within an 80-foot right-of-way.
2 Bus bulbs serve as dedicated waiting areas for transit users while decreasing pedestrian exposure during crossings. Far-side placement is preferable to near-side when possible. Apply turn restrictions for near-side bus bulbs where right-turning vehicles are likely to queue in the right lane. Bus bulbs may be created in the near term without affecting drainage if slightly offset from the curb or designed as a bus-boarding island with a bicycle cut-through.
3Create definition in the roadway using striping, cycle tracks, and narrow travel lanes.
4Cycle tracks require special attention at intersection crossings. Conflicts should be high lighted using intersection crossing markings with the application of color optional. Bicycle signals may need to be applied for bicycle traffic to operate safely along the corridor, though bikes may use pedestrian signals in an interim design. Turning conflicts may be reduced through the implementation of turn restrictions.
5Restricting freight delivery or encouraging off-peak freight delivery is critical to eliminating double-parking obstructions. Off peak deliveries are faster and more cost-efficient and avoid obstruction of the bike lane or delays to buses and local traffic. At peak loading times, dedicated loading zones should be provided to avoid the need for freight vehicles to double-park. Designers may also consider the use of wide parking lanes in these situations.1
- Urban Freight Case Studies (Washington, D.C.: USDOT, Federal Highway Administration Office of Freight Operations and Management, 2009)
“Loading and Delivery Management,” Better Market Street—Existing Conditions and Best Practices, (San Francisco: City of San Francisco, 2011). ↩︎