Approaching Complete Streets design with a typological framework based on land use context to create a connected network

“Complete Streets” as a term was first conceived in December 2003 by Barbara McCann, founding executive director of National Complete Streets Coalition.[i] The term was meant to gain more traction and replace a clunky one—“routine accommodation”—in use at the time to express the idea of including bicycles and pedestrians in everyday transportation planning. “Complete Streets” has gained traction since then. According to the National Complete Streets Coalition, since 2004 over 1,140 agencies at the local, regional, and state levels have adopted Complete Streets policies, totaling over 1,200 policies nationwide.[ii] Today, Complete Streets is more generally understood as streets designed and operated to enable safe access for all users, including pedestrians, bicyclists, motorists, and transit riders, of all ages and abilities.

This broad understanding of Complete Streets has been beneficial in advancing general policies that address the needs of vulnerable road users such as pedestrians and bicyclists. However, it falls short in two aspects critical for successful implementation. First, it does not address the diversity of street types with respect to traditional roadway functional classification and land use context types, and therefore the differences in user needs in each context. Second, it is silent on the need for a connected network of Complete Streets rather than few disconnected “signature Complete Streets” projects. Recent professional thinking has started to address both of these aspects.

All streets are not created equal. In order to create safe and comfortable streets for pedestrians and bicyclists of all ages and abilities, suburban commercial principal arterials need to be designed fundamentally differently than urban mixed-use principal arterials or narrow residential local streets. In the past few years, transportation planning professionals have started to address these distinctions by approaching street design with a typological framework that establishes a combination of roadway functional classification and land use context. Pennsylvania DOT’s Smart Transportation Guidebook, Boston’s Complete Streets Guidelines, and several recent guides published by NACTO are good examples that organize street design guidelines in a typological framework based on different street types.

Kittelson & Associates, Inc. (Kittelson) is currently leading Complete Streets programs and policies based on a typological framework that incorporates a nuanced understanding of different street types categorized by the role of the street (functional classification), the existing and future desired contexts, and the anticipated types of users along the street. One such program being developed on behalf of Florida DOT establishes a context classification system that will be used to determine key design criteria in the FDOT Design Manual for all non-limited-access state roadways. The FDOT context classification system has six different land use context types that broadly identify the built environments existing in Florida. The six land use context types include C1-Natural, C2-Rural, C2T-Rural Town, C3R-Suburban Residential, C3C-Suburban Commercial, C4-Urban General, C5-Urban Center, and C6-Urban Core. Kittelson developed measures related to existing and proposed land uses, development densities, streets and block networks, building heights, setbacks, and socio-economic measures to determine a roadway’s land use classification. Design criteria for all non-limited-access roadways, such as travel lane width, design speed, and types of pedestrian and bicycle facilities, are based on the context classification. For example, an Urban Core arterial can be designed for 25-30 mph speeds, but Rural arterials can be designed for 55-70 mph speeds.

The second aspect absent in the current understanding of “Complete Streets” is the need to create a connected network of Complete Streets. A few disconnected signature Complete Streets projects are not sufficient to create safe and comfortable travel options for all users. In May 2012, Mineta Transportation Institute published “Low-Stress Bicycling and Network Connectivity”.[iii] This pioneering report established a measuring system to calculate “Level of Traffic Stress” (LTS) that bicyclists face on any given street segment and intersection, and highlighted the necessity for bicyclists to feel safe and comfortable at a network level. Since the report’s publication, transportation planners have utilized some version of LTS methodology to analyze the safety and comfort of bicyclists throughout the street network. LTS methodology recognizes the difference in street types, and to some extent land use context, in determining the level of traffic stress. For example, LTS can be low on narrow residential streets with lower traffic volumes and speeds, even if bicyclists do not have separate dedicated facilities. LTS can also be low on high-traffic-volume, high-speed arterials if bicyclists have enough separation from vehicular traffic and protection at crossings and intersections. Not all streets require bike lanes, and bike lanes are not enough of a solution on all streets!

Kittelson has been involved in many projects that utilize LTS methodology to analyze and recommend solutions to create safe and comfortable networks for all users. The firm developed an online interactive LTS mapping tool for the existing street network in Montgomery County in Maryland that is now being used to develop the countywide bicycle master plan.

Another Kittelson project, for the City of Baltimore, analyzed LTS of the existing street network to identify high-priority corridors. These corridors are prioritized for investment in high-quality, low-stress separated bicycle facilities, which would help unlock large islands of low-stress local streets. By targeting a few key arterial corridors, the city could create a large, citywide connected network of low-stress streets for bicyclists.

The next step for the transportation industry is to advance similar methodologies to understand specific network-wide safety and comfort needs for other modes, such as pedestrians and transit users. The big idea is to design a street based on its function and role in the network, its anticipated or desired users, and those facilities and amenities appropriate for the street type to create a connected Complete Streets network that ensures the safety and comfort of all users.

Notes

[i] McCann, Barbara. Happy Anniversary, Complete Streets! Smart Growth America, December 3, 2010. https://smartgrowthamerica.org/happy-anniversary-complete-streets.

[ii] National Complete Streets Coalition. https://smartgrowthamerica.org/program/national-complete-streets-coalition.

[iii] Mekuria, Maaza C., Furth, Peter G., Nixon, Hillary. Low-Stress Bicycling and Network Connectivity. Mineta Transportation Institute, May 2012.