MDOT SHA Access Manual - Practical Design in Access Management

Practical Design in Access Management

Introduction

The Maryland Department of Transportation State Highway Administration (MDOT SHA) is currently developing guidance to incorporating practical design into highway projects. These same guidelines will apply to access permit projects.

This document provides a brief description of practical design in general and how it can be applied to access management projects. All access permit projects should use the Practical Design philosophy. The focus of practical design in access management should be on safety, mitigation, context, and customer service. Each site should be reviewed independently based on the specific site characteristics and project purpose and needs. Design decisions must include justification and documentation.

Objective

Practical Design improves transportation systems by focusing resources on needs that deliver the highest return on investment. The Practical Design philosophy requires critical thinking and sound engineering judgment to achieve the best system improvements, while maintaining a safe and efficient transportation system. Important aspects include:

  • Developing the scope of work to meet the project’s purpose and needs
  • Focusing improvements on safety first
  • Utilizing design flexibility based on safety and operational performance
  • Collaborating on a solution with all stakeholders

Purpose and Need

The basic purpose of any developer-initiated highway project is to provide safe and reliable access to the development for all roadway users. While land use decisions have been delegated to the local governments, MDOT SHA may require roadway improvements to mitigate the impact of development on the safety and operation of the surrounding roadway network. Improvements should be proportional to the proposed development’s impact. MDOT SHA works with local jurisdictions to determine mitigations that are acceptable to all parties.

Scope of Work

Determine the scope of work from the project purpose and need, as described below:​

  • Reliable Access (Mobility)

    1. The developer should complete a Traffic Impact Study (TIS) per MDOT SHA and local requirements to determine the impacts of the development on the existing roadway network.
    2. The developer should mitigate the impact to any movement that is determined to have a Level of Service (LOS) of D or worse using methodologies acceptable to MDOT SHA.
    3. The developer should analyze queues at each intersection in the TIS and mitigate any storage or blocking issues caused by the development.
  • Safety

    1. Access requirements and restrictions shall maintain or enhance safety.
    2. To minimize impacts to all access points, the developer should enhance safety by minimizing and separating conflict points, minimizing speed differentials, and providing adequate sight distance.

Pedestrian and Bicycle Access and ADA

All improvements shall provide for increased safety and access for pedestrians and bicycle traffic in a manner acceptable to the Administration per COMAR 11.04.05.03. All required roadway improvements must also be completed in accordance with Title II of the Americans with Disabilities Act (ADA) of 1990 and Section 504 of the Rehabilitation Act of 1973.

Design

Once the basic scope of work has been determined the design work can begin. Within the MDOT SHA right of way (R/W), all work and materials must conform to AASHTO criteria as well as Administration specifications, standards, and addenda current at the time of the permit grant. The design work should focus on safety and operational performance and the project purpose and need. Design variations and exceptions may be necessary to support the project purpose and need based on safety and operational performance. Documentation must be provided to support these variations.

Approach to Practical Design in Access Management

Project is originated with a purpose and need
  • Safety
  • Mobility
  • Access to development
Scope of work is based on the project purpose and need
  • Mitigation of development impacts (TIS)
  • Enhanced safety
Design is based on safety and operational performance
  • AASHTO Criteria
  • MDOT SHA policy, standards, and guidelines
Design variations and exceptions can be used when necessary to support the project purpose and need
  • Engineering judgment
  • Context sensitive
  • Cost effective
  • Design exceptions
Final Design is selected addressing project purpose and need
  • Collaboration
  • Federal Law
  • Maryland Law
  • Local APF