With forecasted growth bringing an associated increase in traffic, Marshall County leadership needed a comprehensive transportation plan that would enhance mobility and connectivity while preserving the unique elements of the rural community and landscapes. The region is located approximately one hour south of Nashville. Through a Tennessee Department of Transportation (TDOT) Community Transportation Planning Grant, KCI was contracted by the South Central Tennessee Development District to create a set of roadway design standards that would enable the county and its four municipalities to implement a single unified transportation vision as growth occurs.
In recent years, numerous planning efforts were undertaken to identify needs and goals for roadway infrastructure, open spaces and downtown areas, and multimodal facilities, but tasks were localized, and none resulted in uniform design specifications that could provide guidance for upcoming transportation projects.
Our team began their study by conducting an inventory. Roadways were categorized according to their land use context as well as the Federal Highway Administration’s (FHWA) four functional classes: interstates, arterials, collectors and locals. This inventory, combined with an evaluation of multimodal safety, connectivity, and accessibility, laid the foundation for identifying needed roadway improvements that were appropriate for surrounding land use patterns.
Before making recommendations for a roadway classification system or roadway improvement projects, KCI initiated a public and stakeholder engagement process to gather input from members of the business and residential communities as well as key representatives from all of the jurisdictions. Feedback gathered was combined with data collected from an online interactive mapping application, which allowed community members to provide point-specific input on transportation issues experienced every day. These engagement efforts enhanced our team’s understanding of the existing transportation issues as well as future needs of users.
The core focus behind this effort was to provide the right design in the right place that appropriately accommodates existing and expected levels of pedestrian, bicycle, vehicle and truck traffic. After evaluating and analyzing all the collected data, engineers developed a set of refined roadway design standards that are more sensitive to a spectrum of place types and more responsive to the needs of non-motorized transportation users.
It was important that this plan set up the county to accommodate future growth in a way that was logical, maximized infrastructure investments and supported safe movements for a greater variety of roadway users beyond the personal vehicle.
Liesel Goethert, AICPSenior Planner
The established standards are a hybrid of complete streets and functional classification approaches to roadway design with an emphasis on incorporating greater considerations for context and non-motorized user needs into a roadway’s design or redesign. Moving beyond the traditional urban or rural distinction, six context classifications were identified: rural, rural node, suburban/rural, suburban/urban, urban and downtown. All arterial and collector roadways within Marshall County were assigned a context classification based largely on density, land use, setbacks and parcel structure as well as municipal growth planning boundaries. This expanded classification system helps meet the county’s unique transportation needs while also accommodating pedestrians and bicyclists. Design standards within each context differ slightly in order to achieve the intended function of the roadway. Our team developed general descriptions and used pictures, maps and illustrations to help describe each context classification along with a detailed design matrix, which outlines specific roadway guidelines. The document was formatted specifically to help designers easily understand the desired high-level roadway design elements.
In addition to the expanded roadway classification system, planners also identified 29 improvement projects for the county’s arterial and collector roadway system in preparation for forecasted growth. These recommendations were based on an analysis of the region’s demographics, traffic patterns and multimodal system as well as stakeholder and public input. Suggested projects ranged from safety improvements like the implementation of signage, signalization improvements and traffic calming features to high-level bicycle and pedestrian facility recommendations.
This initiative was a first for TDOT in developing an expanded roadway classification system for a county’s complete collector and arterial roadway network that ties land use and transportation decisions together through the use of context-based decision-making and roadway design. It was also the first large-scale TDOT effort to link functional classification, multimodal infrastructure, and the built and natural environment of rural, suburban and downtown areas of a county. The final comprehensive transportation plan sets a standard that will be used by TDOT to evaluate the potential for scaling similar efforts to the statewide level.
“The KCI team executed a thorough public and stakeholder outreach effort that took into account the county’s unique features and vision for the future,” said Johnathan Russell, TDOT Community Transportation Planner Supervisor. “This plan has helped each of the county’s municipalities make decisions related to roadways associated with incoming developments and gives them a path to maintain and improve the quality of life for all of its residents.”
A county-wide vision in terms of prescribed transportation needs and desires beyond just local jurisdiction boundaries was a critical outcome for the stakeholders in Marshall County and will help them as they strategically move forward in funding pursuits for implementation.