Bicycles are legally considered vehicles and therefore legally allowed to operate on any public roadway except where specifically restricted. There are many features and design elements associated with traffic and signal operations that can greatly enhance the attractiveness and safety of bicycling in the roadway.

Standard Plan #265: Vaned Grate

Drain grates : Must be designed such that narrow tires cannot get caught. When new drain grates are installed or existing drain grates replaced, they must conform to the vaned grate design specified in Standard Plan #265. The drain grate design specified in Standard Plan #264 should not be used.

Deck grating : Can be extremely slippery, particularly in wet conditions. Bicycle tires, with their small contact area, are extremely vulnerable to loss of traction. If deck grating must be installed, it must be treated to increase traction and the seam width between the decking and the adjacent pavement should be no wider than .25 inch.

Signal detection sensitivity : Loop detector systems, and any other detection system employed such as camera-based motion detection systems, must be sensitive enough to recognize bicycles or bicyclists. These systems should also accommodate the trend in bicycle technology which is resulting in bicycles being manufactured with decreasing amounts of metal.

Pavement markings for loop detector systems : When necessary, loop detector systems should be accompanied by pavement markings which indicate the location where a bicycle should be located to maximize its disruption of the inductance field. Specifications for this pavement marking are illustrated in Figure 4-17: Pavement Markings for Loop Detector Systems.

Bicycle Parking

On-street bicycle racks : Racks must have the following characteristics:

• are intuitive to use correctly;
• have a no-maintenance finish that won’t chip, peel, or rust. Galvanized steel finishes are preferred;
• support the frame of the bicycle;
• allow a u-style lock to secure one of the wheels and the frame to the rack;
• allow removal of the front wheel and locking it with the rear wheel and frame to the rack;
• have a minimum height of 2.5 feet so it is not a tripping hazard;
• are installed as close to, without being directly in front of, the main entrance(s) of a building or site; and
• have adequate clearance from driveways, curb ramps, transit loading areas and immediately adjacent to shelters, and utility poles.

Get more information on the SDOT bicycle rack program.

Private, off-street bicycle parking requirements are specified in the Land Use Code.

• SMC 23.49.019 Downtown Parking Quantity Requirements
• SMC 23.54.015 Required Parking
• SMC 23.54.016 Major Institutions Parking and transportation
• SMC 23.54.020 Parking Quantity Exceptions

Shared lane markings: Shared Lane pavement markings (or “sharrows”) are bicycle symbols that are placed in the roadway lane indicating that motorists should expect to see and share the lane with bicycles. Unlike bicycle lanes, they do not designate a particular part of the roadway for the use of bicyclists. The sharrow replaces the “Denver Arrow” (bicycle inside an arrow) which was used prior to the development of the sharrow. The design for the shared lane marking is illustrated in Figure 4-18 Typically, the tip of the chevron should be located a minimum of 11’ from the curb face or edge of road where there are no parking restrictions. The tip of the chevron should be located a minimum of 3’ from the curb face or edge of road where there are parking restrictions. At locations where it is desirable to encourage motorist to pass the bicyclist by changing lanes or to wait until they reach a location where the lane widens, moving the marking towards the center of the travel lane should be considered. Sharrows will be placed at the far side of an uncontrolled intersection, at both sides of an arterial intersection with traffic control and at mid-block locations where block faces are more than 250 feet. ere is not enough space for a bicycle lane.

Certain physical characteristics of bicycles require that our transportation system be built and maintained in a manner so bicycles can be safely operated. These characteristics, which are more common in road-style bikes than off-road style bikes, include:

• narrow tires, down to 20mm in width;
• small contact patch with the roadway surface;
• small mass of metal (steel, aluminum, or titanium) compared to motor vehicles;
• high tire pressure, typically 100+ psi; and
• lack of suspension.

These physical characteristics require the following:

Drainage berms: Typical small-scale berms should have an average approach slope of 2%. For example, the approach to a 1.5 inche high berm should be 6 feet long. Berms with shorter approaches increase the likelihood that a bicyclist will lose control of their bicycle, especially those with high pressure tires or without any suspension.

Concrete panels: Should be aligned such that seems should be located outside of the zone that bicyclists commonly travel. For example, this zone is typically 10-12 feet from the curb when on-street parking exists.

Seam width: For new improvements, seam width between concrete panels should be no wider than .25 inch; vertical faulting must be maintained at a maximum of .25 inches.

Railroad track crossings: The minimum setback of a trail from railroad tracks/train should be 10 feet.

On-street channelization: The following features are not required but enhance the operating environment of bicycles:

• Optimal on-street striped bike lanes have a minimum width of 5 feet when adjacent to parking and 4 feet when directly adjacent to a curb or edge of roadway.
• When adjacent to parking, secondary striping is installed to delineate the parking lane from the bike lane.
• Where the edge line separating the bike lane from a motor vehicle lane is 13 feet from the curb or edge of roadway, the secondary striping should be installed no more than 8 feet from the curb or edge of roadway.
• Where the edge line separating the bike lane from a motor vehicle lane is less than 13 feet from the curb or edge of roadway, the secondary striping should be installed 7 feet from the curb or edge of roadway.
• Paint or traditional thermoplastic are not satisfactory materials for bicycle lane symbols. Pavement markings should have a thickness no greater than 75 mil and must have retro-reflective and skid-resistant properties.

Obstruction warning pavement marking: Vertical obstructions within the path of bicycle travel are not recommended, but in some cases may exist. The pavement marking described in Figure 4-20: Obstruction Warning Pavement Marking provides a visual indication to bicyclists plan for an upcoming obstruction.