Arlington's Pedestrian Design Guidelines
- Sidewalks
- Convenient and Safe Crossings
- Curb Radii Reduction
- Nubs or Curb Extensions
- Medians and Islands
- Traffic Signals
- Trail Design
- Wayfinding
Sidewalks
Sidewalks are the cornerstone of the pedestrian system. At the system level, Arlington's goal is to have a sidewalk along at least one side of all residential streets and along both sides of all arterial streets. Numerous programs are in place to help achieve this goal.
The three basic design elements of a sidewalk are width, surface and separation from adjacent motorized vehicular traffic. The minimum width for a new sidewalk in Arlington is four feet. Four-foot sidewalks are found in low density areas such as single family neighborhoods. As adjacent land uses become more intense, the minimum widths for sidewalks increase to six feet for medium density areas, such as townhouses or small commercial areas, and ten feet in high density areas, like the County's Metro corridors. These minimum widths are the clear area of the sidewalk and do not include things like street trees, street lights, traffic signal poles, signs and parking meters.
In Arlington there are three common types of sidewalk surfaces. The most common surface is basic concrete. A majority of sidewalks in Arlington are made of concrete because it is a smooth and durable surface. In many commercial areas, sidewalks are constructed with concrete pavers. Paver walks are viewed as being more attractive than plain concrete and add an urban feel to these areas; however, people with certain physical disabilities may have difficulty maneuvering in them.
A few sidewalks in Arlington have been built with a concrete walking surface and paver borders, "sandwich" style, for walkability with a more aesthetic touch.
The final design element of a good sidewalk is providing separation from motor vehicle traffic. Pedestrians are least comfortable walking directly adjacent to moving cars, trucks and buses, so Arlington makes every effort to provide non-pedestrian, non-vehicular space between vehicle travel lanes and the sidewalk. This space also provides an area for trees, poles, signs, etc. so that the minimum clear widths for the sidewalk can be maintained.
In residential areas, a utility/planting stripe of two-and-one-half to four feet is provided. In commercial and mixed use areas, a space of four to six feet is provided, either as a continuous planting stripe or as an area with street tree pits, street lights, and other street furniture. In some areas where there is not room to provide separation between the street and a sidewalk, on-street parking can serve as a buffer and actually improve the pedestrian experience.
Not every sidewalk in Arlington reflects these design guidelines--in fact, even some of the Couty's most-walked streets fall short in this regard. But meeting these standards is a goal the County continues to strive towards. With each property that redevelops and each street that undergoes improvements, every effort is made to improve conditions for pedestrians.
Arlington also has special design standards for the Rosslyn-Ballston Corridor, the most densely populated segment of the County, to address sidewalk pavings, street tree plantings and street furniture. A central goal of these standards is coordination between different developments to give a more coherent look to the environment from the pedestrian level.
Convenient and Safe Crossings
Crosswalks are critical elements of the pedestrian network that support other transportation modes as well. A crosswalk is defined as any portion of a roadway at an intersection or elsewhere that is distinctly indicated for pedestrian crossing. When crosswalks are marked across the road at an intersection, they are the only legal crosswalks across the road at that intersection.
When no crosswalks are marked, the law defines a crosswalk at each leg of every intersection as "the prolongation or connection of the lateral lines of the sidewalks on each side" (or where the sidewalk would be if there is none). Regardless of crosswalk style or crossing distance, drivers in Arlington are required to yield to pedestrians at all crosswalks.
There are several attributes of good crosswalks, which can be realized through a variety of tools and designs:
- Appropriate Intervals
A reasonable match between the frequency of good crossing opportunities along a street and the potential demand for crossing. - Clarity
Obvious where to cross and easy to understand possible conflict points with traffic. - Visibility
Location and illumination of the crosswalk allow pedestrians to see and be seen by approaching traffic while crossing. - Clear Crossing
Free of barriers, obstacles, and hazards. - Adequate Crossing Time
The time available for crossing accommodates users of all abilities.
In Arlington four types of crosswalk markings or styles are used. The minimum width of a crosswalk is six feet, and many crosswalks are wider, up to 10 feet at crossings with high volumes of pedestrians.
The most common marking is two solid parallel lines. These markings are used at most signalized intersections and at lower-volume pedestrian crossings. At crossings where higher volumes of pedestrians are expected, the ladder style crosswalk marking is used. This style includes two-foot wide bands perpendicular to the solid parallel lines. This type of crosswalk is used at crossings near schools and parks, for mid-block crossings and at intersections with high numbers of pedestrian crossings.
Arlington also uses two types of decorative crosswalks: paver crosswalks and imprinted asphalt walks. Paver crosswalks are common in high density commercial areas, while the imprinted asphalt walks are used more in residential and medium density areas.
Crossing distances also affect pedestrian safety. A goal of the Arlington Pedestrian Transportation Plan is to minimize pedestrian crossing distances, with none exceeding 60 feet. A variety of design features are used around the County to help minimize pedestrian crossing distance. The designs either reduce or break up the actual crossing distance by introducing medians or nubs to the intersections. These design elements are incorporated into new construction projects or are installed as a retrofit to an existing street or intersection.
More information regarding Arlington's crosswalk policies will soon be available online.
Curb Radii Reductions
As shown in the drawing a smaller curb return radius results in a shorter pedestrian crossing distance. Reducing the curb radius also tends to require vehicles to travel more slowly around a corner, which is an additional benefit to pedestrians.
Nubs or Curb Extensions
Nubs extending the curb out into the street are used at intersections and in the middle of blocks to reduce pedestrian crossing distance and to improve the visibility of pedestrians and motorists. Nubs can also help to slow motor vehicle traffic by physically and visually narrowing roads. Nubs have been used for many years in Arlington and are most commonly found on streets that have on-street parking.
Medians and Islands
Medians and pedestrian crossing islands can greatly improve pedestrian safety at street crossings with high volumes of traffic and multiple travel lanes. Medians and islands break and reduce pedestrian crossing distances and allow pedestrians to confront traffic traveling only in one direction at a time. A study conducted by the Federal Highway Administration found that at pedestrian crossings without traffic signals, a raised median or island had the greatest impact on reducing pedestrian-vehicle crashes.
