How we helped
JT Engineering served as the prime consultant for this $1.86 million roundabout project in the City of De Pere. Our design team worked in close partnership with the City of De Pere, WisDOT and all project stakeholders to complete the deliverables in an efficient, cost-effective manner.
By approaching the project as a partnership, we were able to minimize impacts and closures as much as possible and engage in proactive outreach and communication. The project team made multiple field visits to determine the necessary signal equipment upgrades to the adjacent 10th Street intersection and presented several options to the City along with the pros and cons for each option, so the City could be confident in the final selection.
JT is proud to have kept the project both on time under an aggressive schedule and well under budget; the final costs of $1.86 million were more than 20% below the estimated project budget of $2.5 million and were within 1% of construction LET costs. Contract modifications on the project totaled less than 1%. In addition, since the project has been constructed, the delay in the corridor has significantly reduced, which is, in turn, saving public time and fuel every day.
Innovative intersection design
The challenging conditions and constraints at the Main Avenue – Lawrence Drive intersection meant that the design team needed to utilize innovative, outside-the-box thinking to come up with a solution that balanced the needs of the client, WisDOT, the stakeholders, and the public. Compounding the challenge was the expedited project timeline, which gave the project team only six weeks to complete the horizontal and vertical roundabout geometry to keep the project on track.
Before being redeveloped as a roundabout, the signalized Main – Lawrence intersection was part of a corridor that served as a major gateway into the city’s downtown area. An existing roundabout was located adjacent to the intersection, about 500 feet to the west-northwest. Almost 20,000 vehicles utilized the intersection per day, and during peak travel times it became heavily congested, regularly causing traffic to back up into the nearby roundabout and creating hazardous conditions. The proximity of the existing adjacent roundabout meant that a new roundabout was not an easy solution; WisDOT coordination and approval were required, and the agency was hesitant to approve a new roundabout in such close proximity to the existing one. Ultimately, JT’s design staff successfully demonstrated that with careful planning and thoughtful design, a new roundabout would be the safest and most efficient option for the intersection, and were granted WisDOT approval.
Another challenge that required design innovation was the geographical layout of the intersection and its surroundings. Immediately to the north was a 20-acre parcel of developable land that the City was previously unable to utilize due to a limit on any additional access points to the area. Additionally, the north leg of the intersection was serving as the driveway to a McDonald’s restaurant, and the intersection was bordered on the west side by a heavily used WisDOT Park & Ride lot. WisDOT was concerned about impacts to the Park & Ride lot and required that there be no net loss of parking stalls as a result of the roundabout project. JT’s design engineers rose to the challenge, and not only successfully mitigated the loss of parking stalls, but also maintained access to the Park & Ride lot during construction.
Early and frequent coordination with utilities and stakeholders, including owners of adjacent businesses, played an important role in facilitating the project’s successful and efficient delivery. This proactive coordination by JT designers ultimately led to adjustments to the project footprint, avoiding potential utility impacts including a large gas main. We actively listened to stakeholder concerns about minimizing construction time and impacts to their businesses while maintaining adequate property access. We offered and evaluated multiple staging options and worked closely with these stakeholders to determine an ideal closure schedule.
Our designers carefully analyzed the corridor’s existing roundabouts, traffic flow, and driver expectations, then specifically tailored aspects of the new roundabout’s design (for example, lane widths and lane configurations) to maintain a cohesive look and experience while meeting design standards and minimizing the overall project footprint.
Problem solved
The Main Avenue – Lawrence Drive roundabout project was successful on multiple levels, due to a careful balancing of the needs of the client, the public, regulatory agencies and stakeholders.
It solved multiple problems for the public and the City of De Pere by significantly improving the safety and efficiency of a known problem intersection, and by facilitating access to an adjacent 20-acre parcel of land for development. The project also benefited nearby businesses by improving access and allowing more efficient parking lot flow, while minimizing construction disturbance. We were able to build relationships with project stakeholders by listening to and including them in project decision-making, which created positive engagement and strengthened the overall design. Finally, JT worked in partnership with WisDOT to maintain and improve a popular Park & Ride lot adjacent to the project site, benefiting hundreds of commuters on a daily basis.
Congestion relief, safety improved
According to WisDOT, roundabouts offer dramatic safety benefits in comparison to signalized intersections. Replacing a signalized intersection with a roundabout, when appropriate, greatly improves driver safety, reducing the risk of injuries and fatalities from collisions. The Main Avenue – Lawrence Drive roundabout, in addition to improving driver safety, also eliminated the traffic congestion that was present at the previous intersection. This reduced commuter delays and provided environmental benefits by eliminating the need for vehicles to idle, start and stop, thus decreasing the overall carbon footprint.
The project provided important economic benefits as well. For businesses located along the project corridor, the roundabout’s elimination of traffic congestion has improved access points, safety and traffic flow. The new roundabout also enabled the City of De Pere to access and develop a 20-acre parcel of land north of the project site, bringing in a major grocery store-providing jobs and revenue.
Complex Design
Although the Main Avenue – Lawrence Drive roundabout was a relatively small project focusing on one intersection, there were several factors that increased the project’s complexity, including the need to design for cohesiveness within a larger corridor and the requirements of an aggressive project timeline.
Given its location within a busy corridor serving as a primary route to downtown De Pere, the new roundabout couldn’t be designed as a standalone project. Instead, it needed to be conceptualized, analyzed and designed at a system level that took into consideration other nearby roundabouts and the corridor as a whole. To address this, JT planned the roundabout lane configurations with the downstream driver’s destination in mind in order to minimize lane changes within and upon exiting the roundabout. The design team also added traffic loops and updated the existing signal located 300-feet east of the intersection.
An additional constraint of this locally funded project was the tight timeline. The design team had only six weeks to complete the horizontal and vertical roundabout geometry and ensure that the plat would be finished on time. During those six weeks, the design team also had to coordinate with WisDOT to obtain acceptance of the horizontal design and coordinate with utilities to determine possible impacts. During the utility coordination process, we discovered a 20-inch gas main on the corridor and needed to subsequently adjust our design to avoid impacts. We successfully made the necessary utility adjustments while also minimizing impacts to the surrounding businesses and WisDOT Park & Ride lot, keeping the project on schedule throughout the process.
A key component of ensuring that the project stayed on schedule, was limiting the amount of time the contractor would be able to close Main Avenue while maintaining a buildable design to receive competitive construction bids from contractors. After reviewing multiple staging options, JT allowed the contractor two main stages in which they closed Lawrence Drive early, and then allowed a 60-day closure of Main Avenue.
Within this tight timeframe, there were several factors that could have challenged the project’s forward progress, but our experience and professionalism enabled us to respond to issues before they became problems. By utilizing proactive and effective communication with our client and project stakeholders, we kept the project on schedule.
