Pages Menu
Categories Menu


Bikeways, roadways, and non-roadway portions of highways where bicycle travel is allowed must conform to best practices for designs and traffic controls. Best practices go beyond the, often inadequate, minimum standards. These minimum standards include those in the AASHTO Guide, MUTCD, and other associated federal, state, and local design and traffic control device standards. Such a best practices approach, which goes beyond minimum standards, is actively encouraged in federal policy documents (see below for more).

Planning, design, construction and maintenance must treat bicyclists as equal and intended design users in all transportation projects and end-of-trip facilities, including connections to bus and rail transit. Let’s examine these, as well as relevant federal policies, in more details.

1)  Planning – Includes bicycling in system plans, as well as project plans and project initiation documents. Includes oft forgotten amenities, such as way-finding signage. Every non-freeway street/highway MUST be treated as a facility that bicyclists will use, and their needs must be considered. Connecting routes favored by bicyclists is also important, as well as serving the full spectrum of bicyclists. These ideas — particularly that bicycling is anticipated on all city streets — must be the top level policies in sound bicycle master plan (BMP) documents.

Planning Policy Example

City of Long Beach has the following top level policies

(click thumbnails for slide show)

beyond-minimums2)  Design – Ensuring that both the geometric layout and traffic controls used on conventional highways (non-freeway roads) conform to best practices, such as treating cyclists as drivers and not manufacturing conflicts. Such conflicts often result from placing bicyclists to the right of right turning traffic, with either freeway-like features or with bikeways at the road edge. Conflicts can also arise from bikeways that route cyclists into the door zone of parked cars, or otherwise route them into roadside hazards. Features like dual free right turn lanes, shallow angle entry/exit ramps (typical for uninterrupted flow facilities like freeways) should not be used on interrupted flow, conventional highways because they place bicyclists at a speed/movement disadvantage and decrease the safety of bicycle traffic for the convenience of turning/entering/exiting motorized traffic. Traffic signal must reliably detect bicyclists and provide the same level of service as is provided to motorists. Surface standards must ensure that highway surfaces are bicycle tire/wheel compatible. See the I Am Traffic Best Practices Guide for more on this subject.

3)  Construction – Construction projects and construction zones MUST be planned with consideration of bicycle traffic. Best practices must also take into account the speed and potential conflicts in determining how bicycle traffic will be accommodated.

Construction Policy Example

An evolving practice of note is how California specifies such zones in the California supplement to the MUTCD (CAMUTCD Section 6D.101, Page 1044).

Section 6D.101(CA) Bicycle Considerations Support:

There are several considerations in planning for bicyclists in TTC [Temporary Traffic Control] zones on highways and streets:

A. A travel route that replicates the most desirable characteristics of a wide paved shoulder or bikeway through or around the TTC zone is desirable for bicyclists.

B. If the TTC zone interrupts the continuity of an existing bikeway system, signs directing bicyclists through or around the zone and back to the bikeway is desirable.

C. Unless a separate bike path through or around the TTC zone is provided, adequate roadway lane width to allow bicyclists and motor vehicles to travel side by side through or around the TTC zone is desirable.


D. When the roadway width is inadequate for allowing bicyclists and motor vehicles to travel side by side, warning signs should be used to advise motorists of the presence of bicyclists in the travel way lanes. See Section 6G.05 for more details.


E. Bicyclists shall not be led into direct conflicts with mainline traffic, work site vehicles, or equipment moving through or around the TTC zone.


Figures 6H-15, 6H-30, 6H-32(CA), 6H-36(CA), 6H-101(CA), 6H-102(CA), 6H-103(CA), and 6H-104(CA) show typical TTC device usage and techniques for bicycle movement through TTC zones.

4)  Maintenance – The same level of care applied to motorists MUST also be applied to bicyclists. This includes sweeping of on street bikeways as well as off-street pathways. Road and bikeway surface conditions must be brought back to bicycle compatible surface condition when maintenance projects require asphalt/concrete removal and patching. Also important is ensuring that poor surface conditions of existing facilities are upgraded to bicycle compatible design standards during maintenance/resurfacing.

5)  End-of-Trip Facilities – Fixed bicycle parking (racks and lockers) at public and private facilities, as well as the inclusion of fixed bike racks/lockers, clothes lockers and showers at public and private employment buildings for commuters.  These can be accomplished either by encouragement or in policies or ordinances (see Equality).

6)  Inter-modal connections – Bus and rail racks as well as bicycle accessibility and or access to bus and rail transit stations/connections.

Per federal guidance, bicyclists are expected to be given safe and convenient facilities, to be integrated into the decision-making process, and to have state and local agencies go beyond minimum standards.

Furthermore, federal policy calls for considering bicycling as equal to other modes, ensuring choices for travelers of all ages and abilities, including bicycle access on limited access bridges, as well as going beyond minimum design standards.

Federal Policy Recommendations to State and Local Agencies

  • Considering walking and bicycling as equals with other transportation modes: The primary goal of a transportation system is to safely and efficiently move people and goods. Walking and bicycling are efficient transportation modes for most short trips and, where convenient intermodal systems exist, these nonmotorized trips can easily be linked with transit to significantly increase trip distance. Because of the benefits they provide, transportation agencies should give the same priority to walking and bicycling as is given to other transportation modes. Walking and bicycling should not be an afterthought in roadway design.
  • Ensuring that there are transportation choices for people of all ages and abilities, especially children: Pedestrian and bicycle facilities should meet accessibility requirements and provide safe, convenient, and interconnected transportation networks. For example, children should have safe and convenient options for walking or bicycling to school and parks.   People who cannot or prefer not to drive should have safe and efficient transportation choices.
  • Going beyond minimum design standards: Transportation agencies are encouraged, when possible, to avoid designing walking and bicycling facilities to the minimum standards. For example, shared-use paths that have been designed to minimum width requirements will need retrofits as more people use them. It is more effective to plan for increased usage than to retrofit an older facility. Planning projects for the long-term should anticipate likely future demand for bicycling and walking facilities and not preclude the provision of future improvements.
  • Integrating bicycle and pedestrian accommodations on new, rehabilitated, and limited-access bridges: DOT encourages bicycle and pedestrian accommodation on bridge projects including facilities on limited-access bridges with connections to streets or paths.
  • Setting mode share targets for walking and bicycling and tracking them over time: A byproduct of improved data collection is that communities can establish targets for increasing the percentage of trips made by walking and bicycling.
  • Removing snow from sidewalks and shared-use paths: Current maintenance provisions require pedestrian facilities built with Federal funds to be maintained in the same manner as other roadway assets. State Agencies have generally established levels of service on various routes especially as related to snow and ice events.
  • Improving nonmotorized facilities during maintenance projects: Many transportation agencies spend most of their transportation funding on maintenance rather than on constructing new facilities. Transportation agencies should find ways to make facility improvements for pedestrians and bicyclists during resurfacing and other maintenance projects.

Posts in the Engineering Category

Crossing A Double Yellow Line

Posted by on Sep 14, 2014 in Engineering | 13 comments

Crossing A Double Yellow Line

Co-author: Steven Goodridge. What would you do? You are driving your car along a narrow two-lane road when a cyclist comes into view up ahead. Of course, you are a lawful, responsible, and respectful driver. You recognize that the lane is not wide enough to safely pass within it, so you slow down. If your sight lines are limited, you follow behind the cyclist until you reach a point with better sight lines. If you are approaching an intersection where you might have to stop, then you follow behind the cyclist until you are past that point as well. If there is oncoming traffic, you wait for it to clear. Then, you move into the oncoming lane, accelerate, and pass the cyclist, leaving them plenty of room for safety and comfort. When you are safely past the cyclist and their forward right-of-way, you move back into the proper lane and continue on your way. No problem, right? Just another everyday driving maneuver. But what if a traffic engineer decided to have a solid double yellow line applied down the middle of that road? Wouldn’t your passing maneuver be a violation of traffic law? So what do you do? Do you call the police to complain about the cyclist? Do honk or yell at the cyclist to move over? Do you try to squeeze past the cyclist without moving into the oncoming lane? Of course not. You’re a lawful, responsible, respectful driver. Do you follow behind the cyclist until your route diverges from theirs or you reach a point where the design of the road changes? That’s certainly a safe and legal option, but it is inconvenient and it seems unnecessary, since you can see an opportunity to pass safely. Or do you just take the first opportunity to pass safely, legal or not? If you are like most motorists, you take the first opportunity to pass the cyclist safely, regardless of the stripe. After all, the purpose of the solid yellow line is to indicate where it is unsafe to pass, and the purpose of prohibiting drivers from crossing a solid yellow line to pass another driver is to prevent unsafe passing. So if it is safe to pass, then why is the solid yellow line there in the first place? How did we get here? Our surface streets have carried a wide variety of low-speed vehicles – horse drawn carriages, bicycles, tractors – since long before the popularity of motoring. Our traffic laws protect the right to drive these slower vehicles while also defining the limited privileges of overtaking for drivers who want to travel faster. For instance, overtaking drivers are prohibited from moving into the path of oncoming traffic or moving left of center where short sight distance would make this unsafe. The traffic laws clearly state that a driver wishing to pass another driver must wait behind them until conditions are safe for passing without interfering with other travelers. As motoring became increasingly popular over the last century, motor vehicle crashes took a tremendous toll in human life. One of the most devastating crash types involves a high speed motorist swerving or drifting left of center on a  two-way roadway and colliding head-on with oncoming traffic. Highway engineers discovered that marking a stripe down the center of such roads reduced...

read more

Ask i am traffic: Shoulders as Bike Lanes

Posted by on Apr 2, 2014 in Engineering | 2 comments

Ask i am traffic: Shoulders as Bike Lanes

Nick Kasoff in Ferguson, Missouri asks: Our local highway and traffic department has striped a “bike lane” on the shoulder of a busy road. Aside from the fact that it is a bike lane, there are two big problems – the concrete aprons from all the driveways extend across the bike lane (but not into the traffic lane), and much of the bike lane is split between “road grade” pavement and “shoulder grade” pavement by a meandering line. Needless to say, such pavement conditions are very unsafe for a cyclist. I brought this to the attention of the highways and traffic people, and this is how they responded: “This Department considers the shoulder … suitable for a bike lane.” I don’t use the bike lane anyway, but its existence makes motorists much more aggressive toward my presence in the traffic lane. So my question is this: Are there any standards at all for condition of the paved surface in a bike lane? This slideshow requires JavaScript. This crappy shoulder condition problem highlights the disconnect between how engineers and legislators define the roadway. The legislature typically defines the roadway as exclusive of the berm or shoulder and bike lanes as that portion of the roadway set aside for the exclusive or semi-exclusive use of bicycles. The engineers routinely include the shoulder in the definition of roadway and than refer to the legal roadway as the “traveled way”. This nomenclature disconnect sets up the problem Nick is facing, since the engineers consider a bike lane NOT part of the traveled way, but as a part of the engineering roadway via the shoulder, and since shoulder standards are NOT bike compatible, they can tell Nick to suck it up and live with it. Yet if they followed the legal definitions, the shoulder would NOT qualify as roadway space, and could not be converted into a bike lane without upgrading the space to legal roadway (what the engineers call “traveled way”) standards. This slide showing minimum edge bike lane widths from the classes I teach to professionals, shows the disconnect as it relates to shoulders and bike lanes. CVC = CA Vehicle Code, HDM = CA Highway Design Manual. And a similar problem exists for door zone bike lanes:   Dan...

read more

Bicyclist Behaviors & Crash Risk

Posted by on Dec 20, 2012 in Engineering | 17 comments

Bicyclist Behaviors & Crash Risk

Successful bicyclist behavior is driven by knowledge of common crash types and the behaviors needed to successfully avoid those crash types.  Bicyclist behavior comes in a spectrum with three main behaviors, and in this article we aim to briefly describe the spectrum and show how those behaviors fare in common crossing conflict crash scenarios with diagrams and supportive video. There are three types of bicyclist behavior: Pedestrian behavior Avoiding the roadway by using paths, sidewalks/crosswalks, often against traffic flow Edge behavior Operating at the roadway edge or close to parked cars, includes shoulder and edge bike lane use Driver behavior Following the rules of the road by using roadway through lanes and turn lanes as an equal driver The behavior descriptions above meant to describe behavior at a particular place and time, not people, since a cyclist for example who prefers to engage in driver behavior on normal roads, may be required by law to engage in edge behavior in an edge bike lane.  When operating on a crowded shared use path that is away from roads, with high pedestrian volumes, that same cyclist who would prefer driver behavior, may have no choice but to use ped behavior to avoid crashes.  So it is not uncommon for cyclists to engage in multiple behaviors on a single trip. This is why we don’t talk of edge cyclists, though a cyclist may be edge riding on a particular facility, and similar for driver and ped behavior.  It is also important to understand that unlike edge and ped behavior, driver behavior is a learned behavior that must be taught; it is not innate.  So just because a bicyclist who may at present prefer the more common edge or ped behaviors, does not mean that they will never learn driver skills and/or engage in driver behavior, so we recognize that behaviors are not in general fixed and can change over time and exposure to skills training. The value in identifying behavior, instead of cyclists themselves, is its descriptive power in identifying how behavior influences crash likelihood and why some behaviors are more successful than others in an urban environment with driveways and intersections, the places where most cycling crashes occur.  The most common types of crashes are referred to as crossing crashes, where the paths of a turning motorist at a driveway or intersection and a straight through cyclist can potentially cross, creating conflicts and crashes.  Because of this, we often refer to driveways and intersections as crossing conflict areas. The pie chart couplet (right) shows that even though car-bike crashes comprise the minority of cases where bicyclists hit the ground, when expanded to a full pie (at the right side), the crossing crashes comprise about 5/6 of the total number of crashes.  In examining these crossing crash types, we can learn a great deal about behavior and the facilities and laws that enable or restrict behaviors, influence how successful cyclists will be at negotiating urban roads. Crossing Conflict Types Let’s examine the three main crossing conflict types and the effect of bicyclist behavior. The three types are pullout, left cross and right hook. These conflicts occur at driveways and intersections. We’ll examine each individually. Pullout (shown in the diagram at a driveway) A pullout occurs when a motorist leaves a driveway or turns...

read more