Urban Scale

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Great streets not only move traffic, but also serve as public places supportive of a variety of activities. Quality environments are created when right-of-way is appropriately allocated to accommodate all modes of travel and create comfortable and enjoyable public spaces.

Creating a safe and inviting pedestrian environment entails more than just providing sidewalks - it is important to recognize that people walk for different reasons in various types of places, and that a number of specific components influence the pedestrian-friendliness of an area.

Reasons People Walk

The five basic types of walking include:

Utilitarian Walking - People walk to destinations such as work, school or shopping areas. Most auto and transit trips include utilitarian walking to reach the final destination.

Rambling - People ramble as a recreational activity, typically for exercise or enjoyment. Rambling may include walking the dog, pushing a baby carriage, jogging, or walking briskly for exercise.

Strolling/Lingering - In certain settings, people stroll and linger. They may stand on the sidewalk and talk with others they meet, sit on a bench, or people-watch during an outing.

Promenade - People walk to be seen and interact with other members of the community (e.g. high school students who promenade in groups in shopping malls).

Special Events - People walk at farmer's markets, public concerts, parades, arts festivals and other community events.

Types of Pedestrian Environments

Walking environments can be divided into four basic categories based on pedestrian-friendliness:

Pedestrian Intolerant Environments - Walking is unsafe and unattractive in these environments, as shown in the image below, at left. Examples include freeway corridors, certain industrial or extraction land uses, landfills, and major thoroughfares lacking continuous sidewalks. A major characteristic of pedestrian intolerant environments is that they lack pedestrians, either due to a lack of pedestrian accommodations and/or dominance by auto traffic and auto-oriented land uses.

Pedestrian Tolerant Environments - These environments provide pedestrian facilities, but at a minimal level of accommodation, as shown in the image below, at right. Walking is technically safe (there are continuous sidewalks and reasonably safe street crossings), but land use patterns generate very little walking activity. Arterial street corridors, remote or rural thoroughfares, and certain light industrial or warehousing areas will attract limited amounts of utilitarian walking, and will not appeal to recreational walkers or strollers. 

Pedestrian Supportive Environments - These are well-designed residential areas, commercial and employment centers, parks, and recreational areas, as shown in the image below, at left. Sidewalks are continuous and buffered from streets, and wide enough for passing or walking side by side. Land uses are dense enough to attract utilitarian walking trips or recreational walkers and joggers.  Streets are abutted by buildings, not parking lots, and adequate street crossings are provided.

Pedestrian Places - These districts have mixed land uses, moderate to high densities, good transit service, and extensive pedestrian amenities, as shown in the image below, at right. People will walk for utilitarian and recreational purposes. Pedestrian Places feature people of all ages moving between multiple activities. Typically, at least three unique, highly identifiable areas such as outdoor seating, a water feature, public art, or pedestrian-oriented shopping will be located in close proximity.

Components of the Pedestrian Environment

The majority of pedestrian environments are mostly contained by thoroughfare right-of-way. Although pathways through parks and open space and short mid-block connections in downtown neighborhoods function as pedestrian environments, the principal infrastructure for walking will always be the street system.

The roadway corridor, pedestrian realm, and adjacent land uses are crucial elements in the design of pedestrian environments in all place types.

1. The Roadway Corridor Creating good pedestrian environments requires careful attention to the design of thoroughfares, the allocation of space within street rights-of-way, the spacing, length and treatment of street crossings, and intersection signal timing. In general, higher adjacent traffic volumes moving at faster speeds on wider thoroughfares create less pedestrian-friendly conditions.

2. The Pedestrian Realm Also referred to as the roadside zone, this area includes both the sidewalk and the buffer zones on either side that separate the walkway from motor vehicle traffic and link the walkway to adjacent properties. Greater separation from the street is generally provided where higher vehicular travel speeds are present, and additional walkway width in areas with more pedestrian traffic.

3. Adjacent Land Use Sidewalks alone do not create a pedestrian destination. A combination of residential, lodging, retail, restaurant, civic, or employment uses must be present within a contiguous area to draw a significant pedestrian presence. Attractive pedestrian environments include buildings with numerous doors and windows framing the street, a fine-grained street grid, and parking located on-street or internal to the block.

Components of the Pedestrian Realm

The two most obvious characteristics of sidewalks are:  how wide they are and how that width is used.  However, there are many other important characteristics, including shade, separation from the street, urban scale and so forth. The graphic image at right shows the principal parts of urban sidewalks (the pedestrian realm).  Good sidewalks are as much about the orderly arrangement of these parts as they are about width.

a.  Planting Strip/Furnishings Zone.  This is the area between the edge of the sidewalk (usually a curb) and the walkway. In most of the place types – Downtown Main Street, Mixed Use District, Small Town Downtown, and Neighborhood Shops – this area is called the “furnishings strip” and should be paved.  This is the proper place for above-ground utilities – light poles, fire hydrants, signal control boxes, parking meters, etc. – and for various amenities – benches, newspaper boxes, street trees (in tree wells), bicycle parking, etc. 

In single-family detached and other types of low density Residential Neighborhoods, this zone should be designed as a “planting strip” or “parkway” and should be landscaped with ground cover vegetation and street trees.  In higher density Residential Neighborhoods with multi-family housing and in the Office Employment Area, Civic/Educational Corridor and Commercial Service Corridor place types, the choice of whether to provide an urban sidewalk with a paved furnishings zone or a suburban sidewalk with an unpaved planting strip should be based on the ground level land use and other considerations such as overall density.

This zone of the pedestrian realm performs a number of key functions.  Obviously, it provides space for furnishings, above-ground utilities and street trees.  However, it also provides space for snow storage in the winter (so that plows don’t cover sidewalks when they are clearing streets).  It separates the pedestrian walkway from moving traffic in the street, increasing pedestrian comfort and safety.  Finally, it allows the walkways to be lined up with appropriately placed curb ramps and crosswalks at intersections.

b.  Walkway. This is the primary area allocated to walking. Pedestrians can be in the furnishings zone and in the setback area, but most linear walking will occur in the walkway part of the sidewalk. This area should be paved in all of the place types. Recognizing that walking, especially strolling and lingering, is a social activity, the clear zone will vary in width depending on place type and intended levels of pedestrian use. This zone is typically included as part of the street right-of-way, but  is may be located on public right-of-way, adjacent private property, or a combination of both to provide the necessary width for an unobstructed walkway in urban areas.

c.  Frontage Zone. Also known as the setback zone/adjacent land use, most pedestrians do not feel comfortable walking immediately adjacent to a building, wall, or fence. Instead, they tend to keep some "shy distance" away from the adjacent vertical structure. This space is called the building frontage zone, and accommodates protruding architectural elements, stoops, opening doors, vegetative planters, sidewalk displays, window shopping activities, etc.

The frontage zone is typically located on private property, but may extend into the street right-of-way. Many cities regulate how far from this line buildings should be placed (set back). In traditional suburban style ordinances, large setbacks are required and often this area is required to be landscaped. That approach can be appropriate in the Residential Neighborhood, Office Employment Area, Civic/Educational Corridor and Commercial Service Corridor place types, although that will tend to “lock in” a degree of suburban character that can be difficult to “urbanize” later.

In the Downtown Main Street, Mixed Use District, Small Town Downtown, and Neighborhood Shops place types, most modern ordinances require a “build-to” line rather than a traditional setback zone. In these places types, this area should be paved and should serve functionally to extend the practical width of the sidewalk and also as an area suitable for sidewalk seating at restaurants. In some cases, placement of small amenities and furnishings in this area can also be appropriate.

Width and Space Allocation

The proper amount of street space to be allocated to the pedestrian realm varies depending on a number of factors, including the place type, the overall width of the street, the urban scale, and other local characteristics such as climate, drainage system type, and existing building placement.

a. Planting Strip/Furnishings Zone.  This area should generally be between five feet and eight feet in width.  Considerations in determining desirable width of the planting strip/furnishings zone include:

• There should be enough space to provide for natural irrigation of street trees and accommodation of tree root balls.
• This zone should not be inappropriately wide relative to the overall width of the pedestrian realm.  Generally, it should not be wider than the walkway zone.  In areas where existing conditions force a narrow pedestrian realm, the furnishings zone may have to be proportionately narrower, but should not be less than three feet in width.
• In suburban and low density corridors (the Residential Neighborhood, Office Employment Area, Civic/Educational Corridor and Commercial Service Corridor place types) this zone should be landscaped.
• 

  Credit: Charlier Associates

  Narrow sidewalks attached to the curb should be avoided in all place types.

b.  Walkway.  The width of this area should vary with the place type.  Walkways can be too narrow, obviously, but can also be too wide.  Recommended widths by place type are shown in the table below.  Note widths shown are the sum of two walkways – one on each side of the street

c. Frontage Zone. Also known as the Setback Zone and/or Adjacent Land Use, this area should generally be kept narrow on streets where adequate width has been achieved for the furnishings “zone/planting strip” and the “walkway.” 

However, where the public right of way width is too narrow to allow adequate sidewalks, the difference can and should be made up in the setback zone.  In such cases, the setback zone can be used to provide a wider walkway. Considerations in determining desirable width of the setback zone are shown in the table below.

Examples.  Many urban sidewalks suffer as much from inappropriate placement of objects and inappropriate allocation of space as they do from inadequate width. 

The photo below, at left (from the St. Louis region), shows an instance where an inadequate sidewalk is compounded by the inappropriate placement of utilities and careless handling of grade. In all of the more urban place types (Downtown Main Street, Mixed Use District, Small Town Downtown, and Neighborhood Shops) the ground floor of adjacent buildings should match grade with the sidewalk.

The photo below, at right (from Oahu), shows what happens when cities impose suburban standards in urban settings. The planting area between the sidewalk and the building was required by the City of Honolulu because the right of way line ends at the edge of the small green lawn and the buildings have been set back according to minimum setback requirements. 

Honolulu ordinances require this setback area to be landscaped, not paved. As a result, the businesses along this street in Kailua (Small Town Downtown), which include an ice cream shop, a restaurant and small retailers, are denied use of the setback area for sidewalk seating and the walkway width is inadequate for this place type.

The examples below show two streets with well-designed pedestrian realms. The photo on the left is East Pearl in Boulder (a Downtown Main Street). The sidewalk is not overly generous in width but is adequate and the space is well allocated between the three zones of the pedestrian realm. The right of way line where the setback zone begins is discernible by the pavement joint about 18” from the building fronts.

The photo on the right is from Main Street in Longmont (Downtown Main Street). Here the sidewalk width is just right for the street. Furnishings are well-placed. Again, the edge of the public right of way is discernible by the change in paving type.

Pedestrian Network for Office/Employment Areas

Office/employment areas are often located on busy arterial streets. The combination of single-use zoning, large parcel size, and abundant off-street parking in these place types can translate to little pedestrian activity.

Through changes in policy and future urban infill and retrofit projects, these types of areas can become more densely developed and thus more walkable. Existing places that are more suburban in nature should adopt Pedestrian Tolerant as a minimum design standard. The goal should be to develop these places into Pedestrian Supportive environments. These place types shall provide a basic level of accommodation (continuous sidewalks and reasonably safe street crossings) for the limited number of pedestrians present in these automobile-oriented corridors.   

Roadway Corridors in Pedestrian Tolerant environments carry moderate to high traffic volumes (15-25,000 ADT) at speeds over 35 mph. On-street parking typically is not present and bicycle lanes may or may not be provided.

• Crosswalks should be marked.  Street crossing distances shall be limited by using curb radii of 30' or less, a maximum of five travel lanes to cross at once, and right-turn slip lanes that incorporate pork chop islands for pedestrian refuge.
• Crossing frequency should be 330' - 528' with marked and signed mid-block crossings.

The Pedestrian Realm shall provide minimal levels of safe accommodation.

• Sidewalks shall not be constructed at back of curb. A sidewalk planting strip shall be provided to buffer pedestrians from vehicular traffic (on-street bicycle lanes may also serve this purpose).  The grassy planting strip shall be at least 5 feet in width; greater separation is preferred as the speed of adjacent vehicular traffic increases.
• Sidewalks may be built at a 5' minimum width due to the low volumes of pedestrians typically found within these place types.  In areas with greater pedestrian activity, 8' sidewalks are preferred.
• The Frontage Zone in Pedestrian Tolerant environments typically does not consist of building facades, but may include landscape buffers and/or privacy fences between the street and parking lots.  A shy distance of 1' is recommended for separation between the sidewalk and a low wall, fence or hedge or 1.5' along tall walls and fences.  Buffer vegetation shall not encroach into the pedestrian walkway.

Adjacent Land Uses in office/employment complexes, neighborhood shops, and commercial/service corridors are rarely designed for pedestrians.  However, site design should ensure that the following minimum criteria for Pedestrian Tolerant environments are implemented:

• Buildings will likely be one or two stories high. Ideally, setbacks and parking lot size should be controlled so that a height to width ratio (buildings to street corridor) of 1:10 to 1:4 can be maintained.
• Off-street parking lots located in front or on the sides of buildings should not exceed 20,000 sq. ft. Parking lots shall include internal sidewalks or walkway areas every 250'.
• Landscape screening shall provide intermittent breaks for pedestrian access from the street right-of-way into the site.  Privacy fences may screen views but should not limit pedestrian access to/from the street.
• Crosswalks or raised speed tables should be used internally to help identify walk zones across parking lot driveways.

Article

Our transportation network is a regional system. It consists of streets, sidewalks, light rail lines, bicycle lanes, and all other infrastructure that is in place to support the movement of people and goods. The focus of this project is our streets and how to think differently about their development. This cannot be done, though, without also considering the broader transportation network of which our streets are a part.

From a purely vehicular perspective, there is a hierarchy of streets in our transportation system. Traditionally, the roadway functional classification system has been used to describe how travel flows through this hierarchy. East-West Gateway, the metropolitan planning organization (MPO) and council of governments (COG) for St. Louis, is responsible for maintaining and updating the region’s functional classification system. The table at right depicts the current regional classification system.

The table above is based primarily on vehicular travel. Great streets, though, are more than just conduits for vehicular traffic.

They are public places woven through the social and economic fabric of our communities. In this context, the street network is much bigger than the travel lanes that carry automobile traffic through our region. It is a complex system of dynamic components that dramatically affects the quality of our public spaces. If our street network is only a conduit for automobiles, then we are failiing to maximize the massive investment of public revenue into our transportation infrastructure. This principle is at the core of great street planning and design.

Great streets must be "complete". They must move vehicular traffic, yes; but that is only one of many important roles that they can and should have. They should provide access to all users, regardless of economic status or disability. They should stimulate economic growth. They should offer multiple, attractive modes of travel from which to choose. They should provide attractive places for the congregation of local residents and visitiors. For streets to be great, these factors and many others must be considered as we choose how to allocate space along our thoroughfares. 

Space Allocation is a Choice. Historically, the automobile has dominated space along most of our thoroughfares. Growing populations with growing numbers of personal automobiles-per-household have caused us to choose thoroughfares that are good for little else than the movement of vehicular traffic. To make matters worse, when congestion rises along these thoroughfares we have typically chosen to add vehicular capacity by widening the travel way. The result of these choices is a network of thoroughfares that is predominantly unfriendly to pedestrians, transit, and bicyclists. It has also negatively affected land uses along our thoroughfares.

If we want to create great streets in place of these auto-dominated roadways, we must think differently about space allocation along the thoroughfare. Space allocation is a choice, and our choices have consequences. Choosing to prioritize vehicular traffic will often have negative consequences for other modes and abutting land uses. Choosing to prioritize other modes is a healthy part of great street development, but it may negatively impact vehicular mobility along the thoroughfare. This is where the street network is an extremely important consideration in great street planning and design. Choices that may constrain vehicular travel, such as road diets, lower speeds, raised medians, etc., can be offset if the surrounding street network is effectively utilized.

Road diets must consider network context. All of the streets within the regional system work together to provide mobility and access throughout the metropolitan area. Every street serves a specific function within the regional network. This is an important point to remember during the planning phases of great street development. If road diets are considered, the following questions should be addressed in evaluating its merits:

• Does the existing road serve a major mobility function in the region?
• If so, are their parallel streets nearby to help serve potential excess traffic demand?
• If the parallel street system is severed/discontinuous, could improvements to the local road network mend those gaps to provide alternative route choices for excess traffic demand?
• Is there a desire/opportunity to promote transit along the thoroughfare in order to serve excess traffic demand?
• Is there a desire to provide good bicycle accommodations?

Grids are important for great streets. Regardless of whether a road diet is part of a great street development, the street network surrounding the respective thoroughfare is an important component to consider in the decision making process. At the dawn of the street system in America, urban areas typically developed in a "grid pattern". Over time, suburban sprawl led to non-grid development patterns in many areas, resulting in disconnected networks that rely upon select major arterial streets for the vast majority of vehicular mobility.

Transforming these thoroughfares into great streets is a complex challenge, and it is further complicated by the lack of grid network surrounding the respective corridor. If great streets are desired in such locations, be sure to examine the surrounding street network for opportunities to improve connectivity. Sometimes it may be as simple as opening a cul-de-sac to connect with a nearby street. In other cases, more substantial links may be required; but the increased network capacity can allow us to think differently about space allocation along the thoroughfare in question. It may suddenly be reasonable to reduce vehicular capacity along the thoroughfare if network capacity can be improved through enhanced connectivity. A reduction in vehicular capacity along the thoroughfare gives us more freedom in how we choose to allocate space and prioritize other modes.

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