By: Donald Hammack, P.E.
The Florida Department of Transportation (FDOT) recently completed major improvements to a section of the John Young Parkway/S.R. 423 in Orange County.
The $41.8 million design-build project involved the widening of the existing roadway from four to six lanes from Shader Road to the U.S. 441/Orange Blossom Trail intersection, construction of two new flyover bridges over U.S. 441 and the Florida Central Railroad, and a 1-mile new alignment extension to Forest City Road/S.R. 434 at the existing intersection with Edgewater Road/S.R. 424.
FDOT estimates that this stretch of the John Young Parkway serves approximately 37,000 vehicles on an average day, a number expected to increase to more than 51,000 by 2032 due to continuing economic growth and development in central Florida. This project also will serve commuters seeking an alternative route to nearby I-4, where a complete reconstruction, expected to last six to seven years, will begin in fall 2014. The new extension links John Young Parkway to S.R. 434 and completes a continuous, multilane arterial that serves traffic to and from Orange, Seminole and Osceola counties. This segment of John Young Parkway runs north to south through a section of Orlando that includes a mix of businesses, light industrial development, residential communities and parks.
Certain schedules
Led by the team of Southland Construction and Dewberry|Bowyer-Singleton (Southland/Dewberry), the project began in late June 2011 and was completed in October 2013. The design-build delivery process included several innovative design features to meet the ambitious schedule and trim costs. The team worked closely with FDOT District 5, Orange County, the city of Orlando and several utility agencies and owners to address a host of challenges, including maintenance of traffic during construction, maintaining business access along the corridor, a railroad crossing and relocations/installation of numerous utilities.
A main concern to FDOT was the ability to maintain the heavy traffic volumes of John Young Parkway during and after construction. To improve the traffic flow on John Young Parkway, two major bridge structures totaling 2,114 ft in length were constructed to span the existing at-grade intersection at U.S. 441 and the adjacent Florida Central Railroad tracks. A “Texas U-Turn” was constructed just south of the existing intersection to allow turning movements eliminated by the overpasses and maintain access to all of the side streets, driveways and businesses along the roadway. Maintenance of traffic along both John Young Parkway and U.S. 441 was a key priority for FDOT and local agencies. Due to the high traffic volumes, FDOT restricted lane closures between 6 a.m. and 9 p.m. The bridge construction required overhead work, and the southern portions of the bridges were located in the existing roadway footprint.
In compliance with the restricted lane closures, the team developed erection schemes to work within the time constraints. Essentially, the bridge was designed first, then construction stages were tailored to fit within the restricted times. The northbound bridge runs 901 ft with four spans. The southbound bridge extends 1,213 ft with five spans. The bridges feature horizontally curved steel I-girders for the superstructure and both hammerhead and integral piers. The team also successfully maximized the existing roadway by extending milling and resurfacing limits, reducing the amount of reconstruction. Temporary measures included accommodations for pedestrians and bicyclists, as well as business location signs and access driveways during construction.
The city of Orlando and Orange County both identified aesthetics, lighting, signalization, existing utilities and existing roadways as points of interest. Working with these governments, the Southland/Dewberry team developed enhanced aesthetics for the bridge structure. Color, texture and lighting were all carefully considered, and the design incorporated both the city’s and the county’s emblems into the bridge walls. In addition, because the city and county will both maintain the signalization equipment, all signalization infrastructure was designed in collaboration with both entities. The team also worked with both governments on maintaining the use of their roads during construction, therefore enabling access to existing utilities and facilities throughout the duration of construction.
Florida Central Railroads was involved throughout the construction of the project as well—particularly concerning the installation of a new at-grade railroad crossing. Major concerns included overhead work, schedule impacts and railroad impacts. Throughout construction of the project Southland/Dewberry maintained correspondence with Florida Central Railroads to coordinate the construction schedule with their train schedules. To accommodate their needs, the team would receive notification of the current train schedule and temporarily shut down operations.
A critical path
The bridges included in the concept plans provided to the design-build team were five-span continuous, curved, steel, plate girders with post-tensioned, cast-in-place, concrete, integral intermediate piers. The end bents and piers for the southern portions of the bridges were to be located in the existing John Young Parkway travel lanes, which meant that the new ramps to the existing U.S. 441 intersection had to be constructed and traffic rerouted to the ramps prior to the bridge construction at this end of the structures.
Recognizing that the bridge construction represented the project’s critical path, the Southland/Dewberry team brainstormed ideas to allow for concurrent operations as opposed to a linear relationship. The team introduced deck expansion joints in each bridge and switched the integral pier caps from post-tensioned concrete to steel-plate boxes. This approach allowed the northern bridge spans to be fabricated and constructed while the roadway construction south of the intersection was ongoing. The concurrent operations expedited the construction schedule while providing for the maintenance and protection of traffic throughout the project.
The steel integral caps had the added bonus of lowering the vertical profile, which improved the aesthetics and reduced the height of the bridge-approach retaining walls. Considering that the steel erection was a critical component of the project and due to the restricted operating area, maintenance-of-traffic requirements and location of the railroad, the team developed a very detailed steel-erection plan based on the revised configurations, steel shipping restrictions and crane capacities. The plan included the splicing of the steel members on the ground in those areas where the temporary support towers would conflict with traffic lanes and/or the railroad.
Tunneling through
Due to the highly developed nature of the corridor, there were numerous utilities and nine utility owners present. Impacted utilities included water, sanitary, electric, gas and fiber optic. The Southland/Dewberry team self-performed all utility design and relocations, with the exception of the fiber-optic lines, in order to control the schedule of these tasks. Through the utility coordination efforts, a key challenge was revealed early on: the location of a major AT&T duct bank and an existing manhole that, subsequent to construction of the bridge approaches, would be buried under 25 ft of embankment.
Relocation of the access to the AT&T vault would not only have been expensive, it would also have impacted the project schedule by as much as six months. The solution was a unique access tunnel through the bridge-approach embankment, enabling the existing lines and vault to remain in place. A first for FDOT, the tunnel saved AT&T nearly $1 million and preserved the original construction schedule. The tunnel’s elevation was designed to allow for some settling once construction was complete and the solution was proven highly successful.
Direct answer
The completion of the flyover bridges, roadway widening and new extension have improved safety and quality of life in the area. The additional lanes and dedicated turn lanes have improved traffic flow. The bridges have significantly reduced traffic at the previous intersection. And the new alignment extension has eliminated cut-through traffic in the adjacent neighborhoods. Sidewalks and dedicated bicycle lanes also have enhanced the safety of nonmotorized users along the parkway and have improved access to local amenities, including nearby Trotters Park.
FDOT Director of Operations Alan Hyman was among state and local officials gathering at the ribbon cutting. “This project features innovative solutions that increase mobility, safety and connectivity in the region,” he stated. “For the first time drivers have a direct connection between John Young Parkway and State Road 434/Forest City Road.” R&B
About The Author:
Hammack is an associate vice president in Dewberry|Bowyer-Singleton’s Orlando office.
