by Paul Pishal | Sales Director, Black & Veatch’s telecommunications business
Smarter transportation is just around the corner, as the introduction of smarter, more connected transportation systems promise new levels of safety, efficiency and mobility. With the ability to combine digital and physical infrastructure – and empower today’s roadways with Internet of Things (IoT) technologies – tomorrow’s roadways will push beyond the limits of what was once thought possible to become true platforms of innovation.
But making this dream become reality will rely heavily on deploying fiber optic cable networks that enable the advanced levels of connectivity that will support these IoT features. Fiber optic cables in a transportation corridor will help facilitate these emerging technologies, such as connected and autonomous vehicles, smart sensing roadways and smart signage.
Across the U.S., departments of transportation (DOTs) are actively preparing for intelligent transportation systems (ITS) by investing in the digital infrastructure that underpins it all. But there are significant challenges to overcome when designing and constructing these long-distance high-speed fiber networks that will one day support these promised highways of the future.
Microtrenching Offers Solutions
Typically used in dense urban environments, microtrenching is a proven technology that involves digging a narrow trench between one and two inches wide and up to two feet deep. These trenches can hold multiple conduits for fiber. Providers can quickly go down a road and microtrench for broadband networks fiber installation – one truck travels down the road, creating the trench. Another truck follows closely behind to lay the conduits, then one last truck fills the trench with aggregates and/or specialized backfill material.
Broadband Communities magazine reports that microtrenching is being deployed in several cities around the country, including Austin, Texas; New York; San Francisco; San Antonio; and Charlotte, North Carolina. “In these places and others, city planners and engineers use the technique to leverage overcrowded utility corridors in right of ways, providing more high-speed broadband services to meet the demands of the growing population.”
Depending on the methodology, microtrenching is one of the several capabilities that can help ensure a viable, reliable, cost-effective network deployment. For example, it is beneficial in certain scenarios, such as in areas with constructability issues – e.g., across challenging terrain with rocks or streams, or those with environmental permitting concerns, or when there are interconnect issues across ramps and bridges. When time is of the essence, or when variable terrain makes traditional boring or trenching methodologies impractical, microtrenching is an alternative worthy of exploration.
Pennsylvania Turnpike Project
The Pennsylvania (PA) Turnpike stretches 360 miles across the entire state of Pennsylvania. The Pennsylvania Turnpike Commission (PTC) is looking to increase its fiber optic network to support ITS – but their existing microwave network has limited capacity and can’t support the advanced applications that the PTC required.
PTC is launching an advanced fiber optic network project that would increase bandwidth and boost connectivity between their administrative buildings, support automated tolling capabilities to support future autonomous vehicle traffic on the PA Turnpike, among other advanced telecommunications applications for improved safety and mobility.
But the steep, rocky terrain surrounding some areas of the PA Turnpike makes constructability difficult along the perimeter of the highway, as working off-road increases the complexity of both the project design and build. Plus, it would involve lengthy environmental permitting timelines with various state, federal and local agencies. Microtrenching offered a viable solution; embedding the fibers in the shoulder along the roadway simplifies the engineering permitting process because construction would be entirely contained within the PTC’s Right of Way.
The two-phase PTC project involves microtrenching 184 miles to create a trench that is 1.5 inches wide and 17 inches deep. The trench will hold three micro-ducts, with each micro-duct accommodating 288 fibers, each of which can carry 1 terabyte of data. The result is a literal high-speed data lane embedded alongside the highway.
Black & Veatch is conducting the engineering, permitting, procurement and construction of PTC’s fiber infrastructure. This includes the design of the dark fiber, procurement of major materials, microtrenching on the turnpike shoulder, placing vaults, laterals, attachments to bridges, inside plant work at demarcation sites, and fiber installation, splicing and testing.
With the physical construction starting in 2021, the project will ultimately create a 220-mile fiber optic network with 3 million linear feet of fiber deployed. The project is scheduled to complete in November 2021.
Once complete, the PTC project will provide high-speed data communications that will support the Open Road Tolling initiative and other ITS solutions. Having this critical fiber connectivity enables the PTC to achieve its goals of smarter, safer and more efficient transportation. With this digital foundation in place, the PTC will be able to increase its smart transportation functions over time, which includes smart signage and notifications and traveler information systems, while laying the groundwork for future connected and autonomous vehicles capabilities.
Not only will the PTC fiber project enable safer, smarter and more efficient transportation, but installing extra capacity and making this bandwidth available on the open market will offer additional revenue opportunity, helping to offset the cost of investment. Several state DOTs are planning monetization of long-haul fibers that are being deployed along DOT ROWs. The additional fiber capacity that is installed has market attractiveness for carriers or enterprises looking for capacity across states for their data needs. For PTC, the high-capacity network was installed with extra fiber capacity to allow the PTC to lease this infrastructure.
Microtrenching is a technology that is available and continues to be enhanced. It's a recommended solution when an organization is looking to quickly engineer and construct, while simplifying the permitting process to deploy the network. In Pennsylvania, it was tailored to fit the unique requirements of the PA Turnpike and designed to help achieve the high-tech goals of the PTC.
Black & Veatch is bringing their engineering skills and expertise to the project, adapting new developments in this technology that will ultimately land a high-speed fiber network across the state of Pennsylvania. As microtrenching continues to make its way to market, Black & Veatch will continue to promote the methodology as a key component in delivering a viable, reliable, cost-effective network deployment.