The power of the circle

Opinion

Hey there, time traveller!
This article was published 05/04/2016 (3452 days ago), so information in it may no longer be current.

The efficient movement of vehicles improves productivity, which is ultimately good for our economy. However, for these benefits to be realized we need suitable, logical and efficient roadway design and layout. Efficient design helps traffic move with the least amount of friction. One area where improvements can be made in the provision of safe, efficient and environmentally friendly forms of traffic control in Manitoba is by increasing the use of modern roundabouts.

Roundabouts are being installed in numerous jurisdictions across North America. In Alberta, guidelines exist such that “Roundabouts shall be considered as the first option for intersection designs where, in the exclusive judgment of the department (Alberta Ministry of Transportation), a greater degree of traffic control than a two-way stop is required on a paved roadway e.g. a signalization or four-way stop control.” Further, “Roundabouts shall be considered on all roadways including high speed (70 km/h or greater) corridors.”

It is time for Manitoba to aggressively adopt a similar policy. We are not suggesting replacing all four-way stops in Winnipeg, but we are suggesting that some intersections, including those on provincial highways and higher-volume intersections in the capital region, are excellent candidates for roundabouts. As new infrastructure announcements come from all political parties leading up to this month’s provincial election, it is time to consider the use of roundabouts in those promises. Given finite resources, the use of roundabouts provides an opportunity to foster greater mobility and improved safety to more people. There are a number of corridor projects across the capital region where expensive twinning could be delayed by strategic placement of roundabouts that provide the added benefits of improved access management, mobility and safety.

The primary operational benefit of a roundabout is traffic keeps moving. Unless its capacity is exceeded, traffic will flow smoothly. There are no circumstances where traffic has to stop for any reason (with the few confused drivers being the exception). Roundabouts are thus one of the simpler solutions to complex problems of congestion, poorly-timed traffic lights, emissions and lost productivity. Roundabouts can create a net social benefit. If a tradesperson can make one extra call each day, or a business can make one more delivery as a result of more efficient traffic flow, why would we not investigate the potential?

There are several advantages to the use of roundabouts. First, they reduce congestion and boost productivity. When looking at just 10 intersections in Northern Virginia where traffic lights were already present, researchers in the United States found that roundabouts can reduce vehicle delays between 62 and 74 per cent (depending on the intersection), which, in turn, worked out to a savings of 300,000 hours annually in delays. Roundabouts, it seems, save time, money and unnecessary vehicular wear and tear.

Second, when compared to signalized intersections, roundabouts promote friction-free movement by reducing roadway delays, thus enhancing the carrying capacity of our roadways. The reduction in congestion should free up roadway capacities in some instances, thus improving the potential for more business transactions in locations that rely on their associated roadways. In a 2004 paper that examined traffic flows in Golden, Colo., it was shown how a series of roundabouts implemented in a commercial arterial corridor provided a more aesthetically pleasing area, maintained traffic flow and provided additional pedestrian protection. Before and after data in the study demonstrated the changes in traffic volumes, accidents and economic activity: roundabouts resulted in lower travel times (at slower speeds), minimal delays at major intersections and easy access for pedestrians to businesses in the area. Evidently, roundabouts may be good for business.

Third, roundabouts are generally safer than signals. Research in 2007 by the National Co-operative Highway Research Program in the United States that focused on before and after traffic data found that, overall, roundabouts reduced crashes (including those that resulted in injuries) in all instances except for previous use of a four-way stop (where the before/after data were found to be statistically insignificant). Collisions experienced at roundabouts are typically minor due to the low speed and decline in number as drivers become more familiar with how to navigate them. That said, multi-lane roundabouts can have a higher collision experience than single-lane roundabouts. However, this problem has been addressed by improving designs, and collisions on newer multi-lane roundabouts has been reduced.

Fourth, roundabouts require comparatively less long-term maintenance, despite similar construction costs. A 2010 study from the U.S. National Co-operative Highway Research Program argued that roundabouts have a significantly longer service life (25 years) compared to traffic signals (typically 10 years). Further, roundabouts require no additional power or signal-bulb replacement.

Fifth, and finally, roundabouts are climate-friendly. The previously mentioned study from North Carolina found that roundabouts had the potential to save more than 200,000 gallons (750,000 litres) of fuel, not to mention the associated emissions from combustion. Idling vehicles can have a negative impact on the emissions profile of our province. Finding efficient ways of reducing those emissions through revised infrastructure design seems only logical.

Of course, a significant challenge is driver education. Our first-hand observation of smaller roundabouts within Winnipeg suggests that public education would be necessary, but we are confident Manitobans can rise to the challenge.

Roundabouts are not a panacea. Research has shown signalized junctions can be safer and more cost-effective in certain instances. What we are suggesting, however, is detailed assessments be undertaken for the use of roundabouts when cost, safety, efficient traffic flow and net social benefits can indeed be demonstrated. Productivity and efficient transport are election issues, so let’s be open to the options. Similar suggestions to ours can be found in the Manitoba BOLD policy document available on the Winnipeg Chamber of Commerce website.

David Timothy Duval is chair of the transportation leadership council at the Winnipeg Chamber of Commerce and an associate professor in the faculty of business and economics at the University of Winnipeg. Robert Kurylko is a member of the chamber’s transportation leadership council and a senior transportation engineer at Stantec.