DCCM understands that roundabouts come in a wide range of sizes and even shapes. DCCM’s Indiana office is located near the U.S.’s roundabout capital, giving us unique insight and expertise into how these unique intersection configurations can be more than just a traffic solution. When designed with the project users in mind, they improve safety, reduce delays, accommodate all project users, ranging from school buses to semi-trucks, and save communities real money. At DCCM, we have spent years doing exactly that across Indiana, and we want to show you what that looks like in practice.
Keeping our Communities at the Forefront
Yan Zhu, PE, is DCCM’s Roundabout Design Lead with over 10 years of experience delivering roundabout and roadway design across Indiana, Texas, California, and Florida. He is known for developing cost-effective engineering solutions and has built strong working relationships with INDOT and municipalities throughout the state. He understands that every roundabout starts with the community in mind.
When beginning any intersection improvement project, he and his team consider the vehicles that need to move through it, the pedestrians who cross it, and the budget that has to support it. From compact urban roundabouts to rural corridors handling heavy agricultural equipment, Yan and the DCCM team bring the technical depth and local knowledge to get it right.
Designs that Prioritize Safety
Safety and serviceability are at the core of every DCCM roundabout design.
One Lane or Two?
Not every intersection needs the same solution. A single-lane roundabout can handle up to 25,000 vehicles per day, while a dual-lane roundabout can manage up to 50,000. Every roundabout design begins with a capacity analysis to determine the level of service and lane configurations. This analysis establishes how many vehicles the roundabout can handle and informs the geometry of the design. From there, DCCM develops multiple geometric layout alternatives and performs calculations to evaluate impacts to surrounding properties, operating speed, sight distance, and pedestrian safety, identifying the best alternative before advancing the design.
Getting the Speed Right
Speed management is not an afterthought in roundabout design; rather, it is implemented from the start. After evaluating current traffic volumes and queuing conditions to confirm which configuration fits, Yan and the design team develop a pavement marking layout based on state standards, best practices, sight distance, and operating speed. As part of this process, DCCM calculates each leg’s fastest path so that the chicane at each entry point brings vehicles to a consistent speed before they enter the circulatory roadway. When all entry points reach a similar speed, the differential between incoming traffic and the roundabout narrows, and that is where safety improves.
Lower speeds mean shorter stopping distances, less severe conflicts, and better outcomes for everyone using the intersection, whether in a vehicle, on a bicycle, or on foot.
Bringing the Community Along
Roundabouts can be unfamiliar, and DCCM takes that seriously. The team works with clients to build a public education and coordination process that fits the community’s needs. That might mean a single public information meeting with exhibits showing the roundabout’s layout and location. It might mean animated videos showing how vehicles navigate lane usage and turning movements. For communities with no prior roundabout experience, DCCM has helped clients set up a full-scale practice layout using paint in a parking lot, giving residents a chance to drive through the design before construction begins. The level of outreach is always shaped by the client.
Refining Every Detail
From first concept to final construction, DCCM stays in close contact with the client. The team produces project renderings for geometry review, sets horizontal and vertical alignments, and confirms the design meets the community’s needs at every step. The design also accounts for stormwater management and future landscaping, integrating both into the overall layout so the finished intersection functions well and fits its surroundings. Questions are answered. Adjustments are made. The result is a design that works for the people who use it every day.
Prioritizing Safety in Every Roundabout Design
With over 16 roundabout projects designed in just the past 5 years, DCCM brings a track record of safe, efficient, and community-focused intersection design to every project.
Explore our website to learn more about DCCM’s roundabouts and transportation work, and connect with our team to see how our services can support your next community-focused project.
