Getting Ahead of the Curve with Access Management by Scott Cothron, P.E., Sain Associates
Getting Ahead Of The Curve With Access Management AL 181 in Baldwin County Scott Cothron, P.E. Sain Associates, Inc. In Cooperation with: ALDOT City of Daphne, Alabama City of Fairhope, Alabama
What is Access Management? Access management is the planning, design, and implementation of various land use and transportation strategies to maintain traffic flow and safety along a primary roadway, while still considering access needs of various land uses and development types.
Access Management Breaks The Cycle Arterial Improved Deteriorated Increased Level of Service Accessibility More Traffic Higher Land Conflicts Values Increased Changed Traffic Land Use
AL 181 Access Management Plan Joint project sponsors: ALDOT, City of Daphne, & City of Fairhope Problem: AL 181 to be widened from 2 lanes to 4 lanes with median and area is experiencing rapid development Goal: To establish a plan for protecting the integrity of the roadway for moving traffic through south Baldwin County, now and in the future.
AL 181 Characteristics Existing Corridor – Two-lane arterial that travels North-South. Study Area – From 2,000 feet south of U.S. 90 southward to U.S. 98 – a distance of over 15 miles. Future Corridor – Predominately a four-lane median divided arterial with two small areas designed as a five-lane (center turn lane) cross-section.
Why manage access to AL 181?Access management is key in preserving thetraffic movement function of an arterial roadway!!!It’s a reasonable tradeoff between providingservice to a property (Development) and servicingtraffic (Roadway).
The State Route 181 Access PlanThe major elements of focus include standards for: Traffic Signal Spacing Median Opening Spacing Side-Street Roadway Spacing Driveway Spacing Shared Access
Two Primary Deliverables/Tools 1. Report – Background – Standards 2. Plan on Aerial Mapping – Scaled aerials denoting critical access management points
Traffic Signal Spacing 55 mph design speed Signal spacing at 2,600 feet or one-half mile.
Median Opening Spacing 55 mph design speed 1,300 feet, measured from the center of openings along the travel way
Driveway Spacing 55 mph design speed Spacing of 660 feet for a median divided section and 500 feet for a five lane (center turn lane) section.
Corner Clearance at Intersections The distance from an intersection of a cross road to the nearest driveway connection either prior to or following the intersection.
Turn Lane Requirements Left turn deceleration lanes at all median openings Right turn deceleration lanes to all commercial driveways with expected turning volumes > 50 vehicles in a peak hour All turn lanes shall be in accordance with current ALDOT standards
Driveway Throat LengthSuggested Throat Lengths: – 300 feet for mall or supercenter – 250 feet for developments > 150,000 square feet – 150 feet for developments between 100,000 and 150,000 square feet – 50 feet for small strip developments at intersection corner parcels – 30 feet for convenience stores at intersection corner parcels
Grouped Parcels The Plan identifies groups of existing parcels, developed and undeveloped, that will ultimately be required to share access to State Route 181. Most cases for State Route 181 provide one access point or driveway that the grouped parcels must cooperatively use when all parcels are developed or redeveloped. A temporary driveway permit can be issued for a single small parcel developed independently with the understanding that the site plan must provide for future connections to adjacent parcels in order to reach the identified access location on the Plan.
Great Plan . . .But How Do You Implement It? Plan was jointly developed with input from City Planners and ALDOT Adoption of Final Plan by each City Application & enforcement through City land development approval process (subdivision & site plan approval) Approval for access permit to AL 181 controlled by ALDOT
Good in Theory . . .But Does It Work? Can we really balance competing interests for a win / win solution? YES, but it takes time and patience!
Lessons Learned from AL 181 Joint participation in plan development worked well Should have done public involvement during plan development Public airing of plan prior to approval stage Get politicians’ support on record
Contact Information: Sain Associates 244 W. Valley Ave., Suite 200 Birmingham, AL 35209 (205) 940-6420 Scott Cothron, P.E. email@example.com