Maryland Department of Transportation State Highway Administration TSMO I-695, I-70 and US 29
Rossi Group provided transportation planning support to the Maryland State Highway Administration (MDOT SHA), Office of Planning and Preliminary Engineering (OPPE), Project Management Division (PMD) in their Concept Development stage efforts of a potential new project. The project entails potential corridor improvements such as Transportation Systems Management & Operations (TSM&O) implementation strategies within the existing right-of-way of a commuter route in Howard County. The 16-mile long corridor includes I-70 from MD 32 (Sykesville Road) east to US 29 (Columbia Pike) south to MD 100 east terminating at I-95.
Concept Development Stage
The activities in this concept development stage included to conduct project scoping activities, prepare a Needs Study, develop a Purpose and Need statement, develop and evaluate alternatives, and select the recommended alternative. All findings and supporting documents were summarized in a concept report.
Needs Study, Data Collection, Mapping
Rossi was responsible for preparing the corridor needs study at the appropriate level of detail necessary to assess current conditions and project future demands. Rossi developed the base mapping showing existing and proposed conditions on aerial maps depicting opportunities and constrains such as natural environmental, historical, and other sensitive features. The data and information collected included:
Non-motorized transportation data: existing and proposed off-road pedestrian and bicycle facilities such as community paths, neighborhood and regional trails, Howard County Bicycle Master Plan, and pedestrian accident location and rates
Land use and right of way: State and County-owned Right-of-Way, parcel data, zoning maps, existing County and State parks, open space, and recreational facilities such as golf courses, forest conservation easements, neighborhood preservation easements, and utility easements
Roadway data: functional classification; geometric data for travel lanes and shoulders; as-builds; posted and design speed; existing pavement condition; pavement maintenance, rehabilitation, and reconstruction schedule; lighting and signal plans; contours; maintenance issues; and asset condition for guardrails, end treatments, and traffic signs
Structure data: major structures such as overpasses and bridges including current condition and inspection reports; minor structures such as culverts and headwalls; and noise abatement structures
Traffic data: mobility data (annual average daily traffic, travel time index, planning time index), congestion and reliability data from the 2016 Maryland Mobility Report, level of service, crash data, and Candidate Safety Improvement Sections (CSIS) reports
Cultural and natural environmental data: Data was collected using available state, county, and open-source/online GIS data such as the Water Resource Registry, ARCGIS, and eGIS. Data collected included: Designated places, historic sites, waters of the US, streams, floodplain and floodplain boundaries, tracts of forest and significant trees, Forest Interior Dwelling Species (FIDS), National Wetlands Inventory and Maryland Department of Natural Resources wetlands inventory, soils, and previous National Environmental Policy Act (NEPA) studies
Environmental mitigation activities: stormwater facilities including best management practice (BMP) sites including year of completion, nontidal wetland mitigation and stream restoration sites, noise walls including previously identified noise-sensitive areas (NSA), roadside tree and vegetation management and maintenance schedules, and anticipated permitting requirements
Previous studies and correspondence: Howard County Priority Letters, 2008 “I-70 from US 29 to MD 32 Project Planning Study”, previous memoranda of understanding; and correspondence documenting any prior commitments.
Purpose and Need
Rossi developed the purpose and need document stating the project objective in a clear and concise manner.
Develop, Evaluate, and Recommended Alternative
Rossi defined the principal design of the TSMO alternatives and analyzed how the project's need is met. Concept level TSMO improvement alternatives were developed including hard running shoulders; part-time shoulder use; and active traffic management strategies to stay within the existing right-of-way. Environmental, cultural, socio-economic, and right of way impacts were determined. Concept level cost estimates were prepared using the major quantities and cost per mile methodology. Cost estimates included the cost of anticipated stormwater and noise mitigation activities. A benefit/cost analysis was prepared and a final recommendation for implementation presented.
Technical Review and Coordination
Rossi provided the technical review of alternatives developed by others. Review included AASHTO and state and local design requirements for travel lanes and shoulders, offsets, sight distance, and other design parameters. Rossi also reviewed the benefit/cost analysis and traffic impact analysis provided by others. Rossi coordinated with various sections within the organization including environmental, permitting, maintenance and operations, traffic, maintenance of traffic, public outreach, utilities, and construction staff.