I-795/Dolfield Road Interchange Design

Baltimore County, Maryland

KCI performed a project planning study and prepared preliminary and final design plans for the Maryland Department of Transportation State Highway Administration (MDOT SHA) for a new interchange at I-795 and Dolfield Boulevard/Pleasant Hill Road in Baltimore County.

Planning/NEPA. Engineers performed a detailed Stage II planning study and oversaw technical environmental work including unique/sensitive areas. Our team assisted MDOT SHA in preparing the Purpose and Need, developing several alternatives, identifying environmental resources and constraints, and completing environmental documentation. KCI developed displays and presentations in an extensive public outreach effort. In addition to the public hearing, engineers participated extensively in community meetings, business association meetings and briefings of elected officials.

I-795-Dolfield-Road-Interchange-Planning-StudyKCI worked with the MDOT SHA Environmental Manager (EM) and the sub consultant EM in developing a thorough environmental inventory and technical analysis including air quality, noise, community impact, and natural environment impact. Our intensive inter-agency coordination and environmental oversight were instrumental in meeting an aggressive public hearing schedule and ultimately fulfilled NEPA requirements through the development of a Categorical Exclusion. Our team also assisted in preparing the required documentation for issuance of an Interstate Access Permit Approval for the interchange improvement.

Preliminary and Final Design. The selected alternate includes the widening of the I-795 mainline, widening of the Dolfield Boulevard Bridge over I-795, addition of northbound and southbound on and off-ramps and local intersection improvements. KCI lead the preparation of the Director’s Review submittal; structure Type, Size and Location (TS&L) Plans; and Preliminary Investigation Plans. Design tasks included value engineering, partnering in design, CTP estimates, Transportation Management Plan, public meetings, interchange/intersection geometrics, drainage, stormwater management, erosion and sediment control, traffic control, signing and signal concepts, landscaping, JPA preparation, preliminary right-of-way, utility impact analysis, and CCTV Inspection by KCI’s PACP – Certified Operator. Structure design included bridge widenings, retaining walls, and noise walls. Our utility team reviewed design files to develop the preliminary Utility Impact Analysis within the project limits and developed a SHRP2 RISB prototype Utility Conflict Matrix identifying existing utility conflicts for presentation to the MDOT SHA project manager.

KCI assisted in the development of the project charter and issue resolution ladder as part of formal partnering in design. Monthly partnering meetings assist in the development and tracking of action items and meeting agendas.

Stormwater Management. This project is located in the Gwynns Falls watershed in Baltimore County which is designated as an inter-jurisdictional flood hazard watershed. KCI’s design was required to demonstrate Environmental Site Design (ESD) implementation to the maximum extent practical, with no increase in the downstream peak discharges for the 100-year, 24-hour frequency storm event. Also, in project areas where downstream flooding issues or inadequate conveyance were evident, additional management of the 10-year, 24 hour peak discharge was provided. KCI’s tasks included data collection; research existing drainage information; review of archived and as-built data; field investigation and identification of all appropriate points of investigation including outfalls; development of stormwater management volume requirements; computing ESDv targets and impervious area requiring treatment; determining 10- and 100-year quantity control requirements; preparation of the Site Resources Map, layout type, size, and location of stormwater practices including sizing computations; and preparing preliminary grading plans, typical details, and schedules for all SWM facilities including maintenance access, type of control structure, and concept level conveyance/bypass/outfall strategy.