Trailway Design Build – Maybrook

750-miles of scenic treasures and historic sites across New York State have been connected to form the multi-use trail system named Empire State Trail. A source of recreation, economic development and tourism, the new recreational trail, which runs from New York City through the Hudson and Champlain Valleys to Canada, and from Albany to Buffalo along the Erie Canal.

Officially opened December 31 2020, and accessible year-round, the trail provides a safe outlet with off-road trails ideal for cyclists, hikers, runners, cross-country skiers and snow-shoers.

McLaren engineered the 23-mile connector between Hopewell Junction and Brewster called the Maybrook Trailway as part of the expansive infrastructure development. This design build trailway project repurposed a portion of Metro North’s previous two-track Beacon line corridor into a 10-foot wide shared-use bicycle and pedestrian path. After removing one track, the trail now follows the alignment of the railroad line while the other inactive track remains in place for potential future rail service.

Running through a picturesque portion of the Mid-Hudson Valley the Maybrook Trail features rural landscapes, wooded areas seasonal waterfalls, rock cuts, and a crossing of the Appalachian Trail. The 10-foot wide shared-use bicycle and pedestrian path starts in a parking area in Pawling, NY and continued north through two counties (Putnam and Dutchess), five towns (Southeast, Patterson, Pawling, Beekman, and East Fishkill), and the Village of Brewster.

Working closely with Metro-North, and the design-build partner, McLaren designed all aspects of the trailway including final layouts, detailing, and development of specifications to render the Rail Trail complete and fully functional.

McLaren utilized the trailway’s five existing trailheads and two gateways to provide parking areas, access to the trails, and wayfinding for this off-road, shared-use paved trail. Amenities were engineered in accordance with the EST Design Guide including the stone park benches, picnic tables, informational kiosks, trail use guidelines, four bike racks, bike repair stations, and vehicle entry signing. The trailheads are constructed with a hot mixed asphalt driveway apron and access control (i.e. bollards with chain, bollards with steel angle iron swing gate), shoulders, and appurtenances for 8’ and 10’ wide trail sections throughout.

The Bridges

The 31 existing bridges, formerly designed for railroad loads, were redesigned and retrofitted to carry this design build pedestrian and bicycle trailway.  Spaning Metro-North’s Harlem Line, roadways, streams, and cattle crossings these undergrade bridges and are made up of various materials including steel truss, steel deck girder/multi-beam, concrete encased rail-top, masonry arch, precast concrete box culvert, and steel pipe. The new bridges were designed to go over the existing abutments and not put any weight on the abutment structures. Additionally, many of these bridges were used for construction access.

Utilizing an existing conditions inventory for this section of the trailway was a key element for McLaren in determining the design of the Maybrook section. With the goal of retaining as much of the existing structures as possible, we engineered the replacement of four bridges and rehabilitation of the remaining 27 bridges to re-establish the crossings along the rail trail corridor. All undergrade bridges and culverts, and overhead bridges carrying state, county, and local roads over the Maybrook Trailway were designed to a 40-year service life to minimize maintenance and repair costs.

The bridges were modified to carry the bikeway, emergency vehicles (H10 Design Load), provide drop-off protection/railings/fencing, and address drainage concerns. Using cost-effective techniques to minimize maintenance and repair and life cycle costs, the bridges were designed to a 40-year service life.

For the two state highway bridges over Route 311 and Route 164 in Patterson, NY, a minimum vertical clearance of 15’-6” was maintained. These two replacements were designed with future DOT roadway widening / realignment in mind, so the bikeway spans wouldn’t need to be replaced. Work included the demolition and removal of the superstructure and portions of the substructures to accommodate new substructures and superstructures, construction of new substructures behind existing abutments, and construction/installation of new superstructures complete with bikeway decking and drop-off protection/railings/fencing.

One steel truss bridge in need of rehabilitation is located over the Harlem Line. McLaren designed a catchment system to capture construction materials to prevent them from falling on the railroad tracks below. Calculations were provided to prove that the system could handle all anticipated materials.

The McLaren Difference: Applied Ingenuity

Wildlife Protection

Great attention was given to protecting critical wildlife on this project. McLaren engineered permanent fencing along critical and suitable habitat areas, extending 25 feet beyond the limits of the habitat areas. We supported the install 2 feet from the edge of the trail to discourage trail users from wandering from the trail and into critical and suitable habitat areas. To allow for the safe passage of wildlife, a single row of silt fence with 6” to 12” gaps every 100 feet in all other areas were engineered and installed with a minimum 4-inch burial prior to March 31.

McLaren visually inspected for any threatened or endangered species within the work area prior to conducting any work and a double row of silt fence, with a minimum 4-inch burial extending 100 feet beyond the limits of the habitat areas were engineered and installed 5 feet from the edge of the trail. This work was constructed prior to March 31, when bog turtles are in hibernation.

Resiliency

McLaren engineered the trail for climate change resiliency to offset these potential impacts of increased flooding, greater temperatures and wind extremes; as well as climate-induced interruptions in electrical power, communications systems and fuel supplies. McLaren considered riverine floodplains, local runoff patterns, and flooding due to local drainage patterns in the design up to 100-year storm standards.

Drainage improvements (cleaning of existing structures/culverts, and installation of new culverts, pipes, swales, trench drains, and stone diaphragms) as needed throughout the trail corridor and all trailhead parking areas for the calculated stormwater runoff that provides functionality, durability, ease of maintenance, maintenance access, safety, and pleasant aesthetics. Identify and clean existing culverts and cattle passes along trail to promote drainage as directed by the Engineer. The new trail must slope away from existing tracks. Install stone-filled diaphragm and conveyance swales along trail as necessary.

For the proposed more resilient alternative designs, McLaren conducted a cost-benefit analysis to evaluate the future benefits (projected losses avoided) of the project in relation to the project costs. If the future benefits are equal to or greater than the cost, then the proposed activity is considered cost-effective.

Additional Trailway Design Build Services

Signage: McLaren engineered foundations for the various signage including the standard Empire State Trail (EST), MUTCD, and ADA signage along the trail and at all state and county at-grade roadway crossings and trailhead parking areas. Additional trail signage was installed throughout the project corridor warning of narrow sections, drop-offs, private property, protected areas, trail use and safety rules, and that trail users must stay on the trail / stay-off tracks.

Structural Engineering: McLaren designed the retaining walls for the trail and trailheads. Using the existing abutments as retaining walls, the new bridges were designed to go over the existing abutments and not put any weight on the abutment structures.

Geotechnical Engineering: McLaren performed geotechnical evaluations and supplementary subsurface exploration, as well as prepared a geotechnical engineering report for the various elements of the project.

Surveying: Construction surveys, construction stakeout, and as-built surveys were performed.

Permitting: The trail connects with 18 crossings, state routes private drives, etc. McLaren coordinated with the NYSDOT to obtain a fully approved Highway Work Permit. Additionally, McLaren is responsible for the review of the work zone traffic control plan.