Flexible/revised local design standards
City and County of Denver
Since 2002, Denver has used a new street classification system that considers multiple modes of transportation and surrounding land uses. The designations are: residential streets, main streets, mixed-use streets, commercial streets, and industrial streets.
Denver's street typology and classification system help the city and developers create streets that meet community needs. The system recognizes how streets interact with surrounding land uses and how people may use different types of streets to access different types of destinations. Highlighting these connections helps improve and preserve multi-modal and pedestrian friendly streets, an important element of livable communities.
Streets have been historically classified by design and operational characteristics that relate primarily to the movement of cars. As a consequence, street design is often less sensitive to the needs of non-motorized modes and transit. The City and County of Denver, believing a better balance was needed between functional classification, adjacent land use, and competing travel needs, decided to "classify" its streets according to functions related to how people travel on the roads (walking, biking, driving, etc) and what destinations are served by the roads (residential, mixed use, etc). It also created a street typology system designed to prioritize various roadway design elements by looking at factors related to both adjacent land use and functional classification. Denver's street types and functional classifications are designed to bring consistency to the process of planning and improving multi-modal streets, helping ensure that land use and roadway function are given due consideration. This guidance helps planners develop transportation improvements that support local land uses and connect to the rest of the street network.
Blueprint Denver, an integrated land use and transportation plan completed by the City and County of Denver in 2002, defines six roadway functions. Three of these - arterial streets, collector streets, and local streets - are part of the traditional functional classification used by federal, state, and local agencies. Two are "special Denver categories": Landmark Streets and One-way Couplets. Landmark Streets are significant for historical reasons and have influenced the development and unique physical character of the city. One-way Couplets are pairs of one-way streets that function as a single, higher-capacity street. Couplets are usually separated by one city block. Finally, the plan designates a new street classification: Downtown Access Streets. These streets serve densely developed mixed-use areas within the downtown area, and are designated as multi-modal facilities.
Augmenting the functional classification system are five street typologies: Residential Streets, Main Streets, Mixed-Use Streets, Commercial Streets, and Industrial Streets. These typologies allow Denver planners to more precisely characterize streets, using terms such as "mixed-use arterial" or "residential collector." State highways are included in the typology system, but not controlled access highways (freeways). Blueprint Denver defines each of the typologies as follows:
"[M]ulti-modal street types and functional classifications deal with how a street interfaces with the adjacent land use and how the street is intended to function from a mobility standpoint. Both are important elements to consider when attempting to create seamless connections between several transportation modes. As tools to implement Blueprint Denver, each element gives direction to City staff, elected officials, neighborhoods and others who are undertaking more detailed planning efforts to develop project-level recommendations."
The two-year effort to develop the street typologies was led by Denver Community Planning and Development and the Public Works Transportation Planning office, with the help of a consulting team and a 42-member Land Use and Transportation Advisory Committee. The committee represented various neighborhood groups and public agencies, including Historic Denver, Denver Environmental Health, the Denver Planning Board, the Denver Water Board, and the Neighborhood Resource Center.
Where sufficient public right-of-way exists, all priority design elements may be accommodated. Within constrained public rights-of-way, however, trade-offs between priority design elements are required to balance the functions of the various travel modes.
Blueprint Denver's street typologies are often used as a starting point in the development review process by the Denver zoning, planning, and engineering staff who review private development proposals. A Denver development review committee, named "BlueBridge," is responsible for designing cross sections for street reconstruction projects and land use redevelopment across the city, and has begun to rely on the Blueprint Denver typologies. The functional classifications are shown in Figure 1.
Figure 1 Denver Street Functional Classification | Blueprint Denver, City of Denver, 200.
In addition, the multi-modal street concept has been included in zoning amendments, transportation and land use plans, and in design guidelines for local redevelopment projects: the Stapleton Airport Redevelopment Project, the River North Plan, the Downtown Multimodal Access Plan, and the East Colfax Plan.
Blueprint Denver and the Denver Comprehensive Plan recommend higher density, pedestrian friendly, mixed use development along Denver's commercial corridors or "Main Streets." Three Main Street zone districts were established by the Denver City Council in 2005 to encourage a strong mix of housing, office, and commercial uses in transit rich places and commercial corridors. The Main Street zone districts are implemented using "form-based codes" that provide standards for appropriate building form while allowing flexibility in uses and reducing parking requirements.
Denver Public Works, with major support from Denver Community Planning and Development, has begun to develop the Strategic Transportation Plan (STP). The objective of the STP is to determine the types of transportation investments Denver needs to accomplish the vision of Blueprint Denver. The STP represents a new approach to transportation planning. Instead of simply forecasting future auto travel on Denver streets, Denver has developed a transportation model that forecasts expected increases in person-trips, in order to evaluate the magnitude of impacts caused by all types of travel. This person-trip data will give Denver the ability to plan for bicyclists, pedestrians, and transit as well as for street improvements. The STP is the first step in identifying the needs for every major "travel shed" in the city. The STP will include concepts for how to meet transportation needs, including a prioritization of corridor improvements.
The Stapleton Redevelopment Project is the largest infill redevelopment project in the nation, occupying the 4,700-acre (7.5-square mile) site of the former Denver Stapleton International Airport. When build-out is complete in 2016, the area will boast 12,000 homes, 10 million square feet of office space, 13 million square feet of retail space, and 3,000 hotel rooms. The Stapleton Redevelopment Project will bring 35,000 jobs and 30,000 residents to the area. Although the original Design Guidelines for Stapleton, published by the City and County of Denver in 1999, pre-date Blueprint Denver, they specifically address the need for context-sensitive streets that balance the needs of all users. The guidelines call for urban design elements, such as trees, tree lawns, on-street parking, building entries, and accommodations for bicycles and pedestrians in addition to cars and transit. The Blueprint Denver street typologies add an additional layer of context-sensitive design to an already forward-thinking document. They have led Stapleton project planners to designate one residential collector and one residential arterial, and to construct several residential streets with 30-foot-wide cross sections.
The Downtown Multimodal Access Plan, completed in 2005, provides a detailed, integrated plan for vehicular, freight, pedestrian, bicycle, and transit access into and throughout the downtown area over the next 20 to 25 years. The plan takes into account the relationship between long-term land use planning, infrastructure improvements, and streetscape and urban design elements needed to ensure multi-modal connections. The City and County of Denver, the Regional Transportation District, and the Colorado Department of Transportation (CDOT), as well as the Downtown business community, sponsored the study.
The West Colfax Corridor Transportation Study, completed in 2010, identifies existing conditions and recommendations for improvements along West Colfax Avenue. This mixed use corridor contains approximately 440 acres of residential, commercial, retail, office, industrial and institutional uses. The study cites recommendations for multi modal improvements to the West Colfax corridor from Blueprint Denver, based on its classification as a "mixed use arterial corridor" and proximity to "Areas of Change" neighborhoods. Extensive analysis of pedestrian conditions along the corridor, including a pedestrian level of service analysis was performed as part of this study. The study includes many recommendations taken from the street classification system for improvements to mixed use streets, such as improved sidewalks, moving utilities underground, narrowing crosswalks and adding additional medians for traffic calming.
The Better Denver Bond Initiative, a bond initiative passed in 2007, is designed to invest in Denver's infrastructure to improve public infrastructure and facilities. Two hundred and eighty projects are expected to be completed by 2011 under this program. According to the Bond rules, any street eligible for full reconstruction is required to use asphalt or concrete appropriate to the street classification (designated by Blueprint Denver). With a large number of street improvements planned, there is an opportunity to use the street classification system to improve the consistency and connectivity of Denver's street network. Complete repaving of a street provides opportunities to create street elements for non-motorized modes, such as constructing bulb-outs at intersections or painting new bicycle lanes.
Although Blueprint Denver's street typologies are works in progress, they are gradually becoming part of the culture in land use development, zoning, and the design of transportation improvements in Denver. These typologies help developers and planners make connections between different land uses in Denver and provide access by different travel modes. The greatest challenges occur with infill redevelopment. It can be difficult to retrofit existing streets with high volumes of traffic and constrained rights of ways in a manner consistent with the multi modal street principles.
Streetscape changes can be a gradual process and require the cooperation of planners, engineers, and public works departments.
The City of Denver was acutely aware of this when it went about the process of introducing new street typologies to guide multi-modal street design. The Planning and Public Works Departments worked closely together to develop street cross sections for the Public Works Standard Right-of-Way Cross Sections and Utility Locations Rules and Regulations that are consistent with the new street typologies. Engaging the various stakeholders early in the planning process helps reduce potential conflicts later.
Senior City Planner,
Denver Department of Public Works,
Division of Policy, Planning & Communication.