Our roundabout planning and design group is at the forefront of providing specialized solutions to improve the safety of public streets. Science and solid experience is the foundation of our approach to roundabout design. Roundabouts generally contribute to more efficient traffic operations, lower lifecycle costs, and environmental and community benefits. Our team integrates their leading-edge experience to address each unique set of circumstances with a tailored design solution. We provide the following technical services:

  • Analysis, planning & review to evaluate roundabout feasibility
  • Direct design applies our depth of experience to create complete roundabout design packages
  • Design oversight assures agencies of the correct site selection and design quality with the highest degree of skill
  • Micro-simulation delivers powerful system-level traffic analysis plus public relations applications
  • Public education and outreach offers effective, customized facilitation and presentations to inform and engage the community
  • Research and publication efforts are continuously feeding and propelling the design practice

For further information, contact:

Mark Lenters
Tel: +1 608 216 2059
Email: Mark Lenters

Cony Rotary, Eastside Rotary, Augusta, Maine USA

This urban intersection was configured as a rotary and had the highest crash rate in the State of Maine. GHD’s roundabout team conducted a study to document the degree to which the deficiencies were affecting safety and capacity of the intersection. Pursuant to the initial study, we developed geometry, pavement marking, and signing changes to remedy the safety and capacity deficiencies.

Additional intersection capacity was required due to the proposed redevelopment of a nearby property. Approval of the redevelopment plan for the property hinged on gaining additional capacity at the rotary intersection. The design that was implemented reconfigured the rotary to adhere to modern roundabout operating characteristics addressing the safety and capacity limitations. All of the modifications were designed to fit within the original intersection footprint, eliminating the need for additional costly urban right-of-way.

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Gahans Road – Bargara Road Intersection Project

The upgrade of the intersection of Gahans Road and Bargara Road in Bundaberg, Queensland presented a challenge to overcome merging traffic issues. The design needed to incorporate the upgrade of a nearby street intersection and a cane train crossing.

Working for the Department of Main Roads on the intersection upgrade, GHD took into account traffic merging from a number of side streets into a major arterial road. The design allowed for an additional ‘fourth leg’ for traffic from the proposed Bundaberg Ring Road and the existing cane railway crossing.

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Haymarket Infrastructure Project, Lincoln, Nebraska

Roundabouts were utilized at two key intersections to address the future traffic concerns of the new Haymarket redevelopment project being completed by the City of Lincoln and the University of Nebraska.

Our tasks for the project included: the optimization of the horizontal geometrics and reviewing the vertical geometrics, jointing, pavement marking, signing, and lighting. GHD’s roundabout team was able to optimize the roundabouts for safety and capacity without impacting the overhead bridge’s abutment and piers with university parking lots and the railroads right-of-way. Our team presented mitigation techniques to improve the roundabouts’ operations during event traffic.

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Larry Uteck Blvd Roundabouts

Nova Scotia’s three multi-lane roundabouts in Halifax are delivering significant safety and time benefits to drivers. They are designed to help with safe entry to and exit from the highway and to reduce backups during times of heavy traffic.

In 2009, GHD was engaged by the Nova Scotia Department of Transportation and Infrastructure Renewal to design the roundabouts along Larry Uteck Boulevard.

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Roundabout revolution

Streets in many parts of Canada and the USA are being transformed with roundabouts. Once unique to Europe, these circular intersection points are increasingly being adopted in the Americas to reduce congestion and accidents.

In Lincoln, Nebraska, GHD was engaged to address an increase in traffic resulting from the West Haymarket Redevelopment – a 400 acre project designed to revitalise the downtown and haymarket districts. With 7000 planned parking spaces and a 16,000 seat arena forming part of the development, the solution was required to cater for an influx of vehicles, particularly during event periods.

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Trafalgar & Hale Roundabout

In 2010, London, Ontario opened its first major roundabout as part of a railway grade separation in the east end of the city.

The railway is a CN Rail mainline on one of the most heavily-used corridors in Canada. It is adjacent to a nearby rail-marshalling yard and previously bisected two closely-spaced T-intersections. Busy conditions along the railway line, along with area traffic growth, had led to increasingly congested conditions at the intersections.

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Waioru Interchange

The AUD$62 million Waiouru Interchange project represents a significant link in Auckland’s transport network. Manukau City Council and Transit New Zealand commissioned GHD as design consultant and then construction contract administrator on the project.

Key features of the project include two grade separated interchanges, the widening of more than two kilometres of motorway, the construction of local arterial roading as well as a large roundabout and a 200-metre long bridge. This challenging project required carefulcoordination to avoid interference with an adjacent power station cooling pond.

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Mark Lenters

Mark Lenters – Service Group Manager

Mark has 28 years' of continuous intersection safety and design experience underpinned by highway engineering, traffic engineering, transportation planning, and project management knowledge. Since 1986, he has worked equally in the public and private sectors, broadening his understanding of the needs of public agencies. Mark has developed nationally renowned skills in roundabout design, facilitation, training, and safety reviews, successfully leading dozens of small and large multi-disciplinary teams in the process. Mark is a member of the ITE and TRB National Roundabout Committees.

Position: Service Group Manager
Tel: +1 608 216 2059

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Andrew Duerr

Andy Duerr

Andy was part of the early days of the roundabout revolution, contributing to the first designs in Maryland when no modern roundabouts existed in most of the U.S. He has diverse experience in highway design, including roundabout feasibility studies and peer reviews; roundabout policy and publications; traffic studies; horizontal and vertical alignment design; hydrology/hydraulic design; storm drain design; erosion and sediment control plans; traffic control plans; signing, pavement marking, and lighting plans. Andy has managed projects from project planning and preliminary engineering to the development of final contract plans and specifications for Pennsylvania Department of Transportation (PennDOT), the Pennsylvania Turnpike, Maryland State Highway Administration, and Virginia Department of Transportation assignments.

Position: Project Director
Tel: +1 717 460 8958

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Philip Weber

Phil Weber

Phil has over 18 years’ experience managing numerous transportation engineering and roundabout projects in Canada and the U.S. His work has encompassed transportation planning, traffic engineering, geometric design, and road safety. Phil’s experience also includes feasibility work and Intersection Control Studies requiring capacity and safety analyses and associated life cycle costing. He has designed over 100 roundabouts, and his designs have incorporated high-speed approaches, complex signing and multi-lane configurations with bypass lanes or spiral striping. He has seen over 40 roundabout designs through to construction to date.

Position: Service Line Coordinator
Tel: +1 905 752 4352

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Australia and New Zealand

Graeme Robinson

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Graeme has more than 40 years’ experience in the area of civil design and project management of major road infrastructure projects for local and state government authorities. He has held the role of Project Director on large civil related projects and is currently a member of an Alliance Leadership Team for a key infrastructure project in NSW. Graeme brings a wealth of experience to any road system projects.

Position: Service Line Leader – Road Systems
Tel: +61 2 49799925

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