Kings Canyon Expressway Requires Road-Spanning Conveyor System
Moving Material: Vulcan Materials Utilizes a Conveyor System to Speed Kings Canyon Expressway Project
Benjamin Franklin said, “If you fail to plan, you plan to fail.” This saying, which has become a cliché, is applicable to just about everything in life, including construction. Anyone who has been involved with a major construction project knows that a great deal of thought and planning are involved to ensure things go as smoothly as possible. However, sometimes even the best plans can benefit from an unplanned circumstance.
The Kings Canyon Expressway on State Route 180 originates in Fresno, California, and leads beyond the city limits, through Fresno County, and is a direct route to Kings Canyon National Park and Sequoia National Park. Due to the expansion of the population in the valley, the California Department of Transportation (Caltrans) determined that State Route 180 needed to be widened. So, the road is being converted from a conventional two-lane highway to a four lane expressway.
The third and final phase of the construction began last summer and is expected to be completed in the Spring of 2020. The $55 million final phase covers 4.5 miles and will take commuters beyond the last rural community where there is a drop off in traffic.
Adding to the challenge of converting the highway to an expressway is the fact that the bulk of the expansion – 75 to 80 percent – is taking place on the north side. Neil Bretz, Project Manager for Caltrans who has overall responsibility for the project says, “We are moving the whole highway due north. The new alignment is necessary because expansion was limited on the south side because of environmental concerns and historical buildings.”
The area that is being worked on is a well-traveled route. Using trucks to transport the construction materials via the highway would mean more traffic and an increased potential for accidents. Vulcan Materials, a major producer of aggregates-based construction materials, including asphalt and ready-mixed concrete, is providing the materials for the Kings Canyon Expressway widening and is acting as a subcontractor on the project. One of Vulcan's facilities is located right next to the highway. Bretz says, “As we advanced to the East, we got closer to the plant, and their main entrance is less than 100 yards off the highway.”
One would think having the yard located just on the other side of the road from the jobsite would be a great benefit. However, with a busy two-lane highway in between where the materials are and where they need to be transported to, the benefit was lost. The trucks needed to transport the material added to the already congested highway. The extra trucks entering and exiting the highway also increased the potential for accidents.
So close, yet so far away. Then one of the Vulcan Materials’ employees had an idea. He brought the idea to Security Paving, the prime contractor. Use a conveyor system to transport materials over the highway. Caltrans has utilized a conveyor on some previous projects, but as Bretz notes for such a system to work, many factors have to come together. One factor is the location of both the project and the materials. In this case, that centered around Vulcan Materials. While Vulcan Materials has been involved in a number of projects with Caltrans in the past, their inclusion on this project was purely coincidental. Other factors in utilizing a conveyor system include economics.
However, the biggest factor was safety. During the summer in particular, the Kings Canyon Expressway is highly trafficked as people are headed to the national parks. With the trucks entering and egressing into the Vulcan Materials plant and onto the highway, there was increased potential for accidents. "Safety is a big issue for us and we approved the conveyor system because it would lessen truck traffic and therefore be a huge reduction in potential accidents," says Bretz.
For the contractor, the benefits are primarily financial. The contractor has materials transported to the site in a quick efficient matter. Having the materials on site allows the contractor to make the best use of his equipment. He can also utilize larger off road equipment as he does not have to concern himself with navigating the highways.
Finally, motorists win as well. Less trucks on the road improves safety and means less overall traffic. Therefore, there are fewer slowdowns (which tend to increase accidents), and traffic is flowing more quickly.
Putting the System in Place
With the stars aligned, Caltans quickly approved the unique and innovative suggestion, and the conveyor system was built. From the state's perspective, the conveyor system has a couple of benefits including relieving traffic congestion and reducing vehicle emissions.
Upon receiving approval, Security Paving had Vulcan Materials put the plan into action and make use of the conveyor system. The conveyor system itself is pretty simple as it is a rubber belt on a set of rollers. The system is on a small bridge, and it is used to move dirt and other conventional materials. The entire system is 300 to 400 feet long and takes the materials from the plant that is on the south side of Kings Canyon Expressway to the north side. At that point, the materials are stockpiled. The contractor takes the materials from the stockpiles as they are needed. Over the course of the project, Caltrans says the conveyor system will transport 800,000 tons of materials and remove 35,000 truck trips. It's expected that the conveyor system will be in use for six to eight months.
There’s another benefit that the state, contractor, and commuter will all appreciate: speed. Bretz notes that the conveyor system is allowing the contractor to run ahead of schedule. "We're pretty confident that the project will be done sooner than our original projection. While this does not lead to savings for the state, we're happy for the safety benefits which is more than enough for us."
The quickened pace of the construction in this aspect has helped to offset challenges in other areas. As part of the widening of the road, bridge work had to be done. Six significant water crossings required structures and two smaller irrigation channels were piped. Environmental issues arose with this work, which caused a delay.
Caltrans’ strong partnerships with its contractors encourage innovative thinking. In this case, a solution was created which is a win for all parties.