Vision Zero at the Edge

By David Holtzman

You've heard of Vision Zero, a campaign to eliminate serious traffic-related injuries and deaths on our streets. Many big cities in the U.S. have signed on to the campaign, setting goals to reduce accidents for pedestrians and cyclists by slowing vehicle speeds and providing more visual cues to alert drivers of what's going on around them.

But how do traffic calming tools work in a more highway-oriented, suburban, or rural context, where much higher speeds are the norm and the environment for walking or cycling is often dismal?

Planners and engineers in several states and localities have tried novel approaches to slow down motorists on highways where the mere sight of a pedestrian is often a surprise. These roads, built mostly for drivers rather than other users, statistically have terrible crash rates. Rural areas, where speed limits even on two-lane roads often exceed 50 miles per hour, account for 57 percent of all fatalities in crashes, according to the most recent data available from the Federal Highway Administration. The primary goal of making changes to the traffic pattern in most of these environments is to prevent injury or death to people in their cars. In some cases, though, safety improves markedly for pedestrians and cyclists, too.

Roundabouts gain a foothold

The roundabout, although common in many countries in Europe, is rare in most states. Not so in Wisconsin, where the state transportation agency and many planners have adopted it with gusto. Brown County (pop. 256,670), which is anchored by the city of Green Bay, has 72 roundabouts, more than anywhere else in the state (and perhaps the country). The county started building roundabouts in 1997 and hasn't looked back.

"We're the Johnny Appleseed of roundabouts," says Cole Runge, principal planner for the Brown County Planning Commission. "We wanted to improve safety, save money, improve multimodal accessibility, and make places. It seemed like roundabouts could achieve all these goals."

The first two roundabouts Runge helped build in 1999 are near middle and elementary schools on the boundary of two suburban villages, Howard and Suamico. Before construction, the speed limit on the arterial that separates the schools from adjoining residential neighborhoods was 45 to 50 miles per hour. Children had to cross the road to get to school, and there were a lot of accidents.

"The schools did not allow kids to cross the road — they'd be bused across the street," Runge says.

The number of crashes dropped from five in one year, with 11 injuries, in 1996 to zero in 2000, the first year after the single-lane roundabouts were installed. Although a 15-mile-per-hour school zone speed limit had been in place for years, it took construction of the roundabout to force drivers to slow down. The roundabouts spurred the villages to build more sidewalks along the arterial, adding to a sense of safety in the area.

When Runge and colleagues tried to introduce a third roundabout a few blocks away, they ran into resistance from some who wanted to use the newfangled intersection concept as a political tool, he recalls. That roundabout was rejected in a referendum. But since then, roundabouts in the county seem to have found broad acceptance from the public.

Roundabouts in Brown County aren't just on secondary arterials. The county has worked with the Wisconsin Department of Transportation to put a set of roundabouts at opposite ends of an interstate interchange. Roundabouts have shown up adjacent to downtowns, too, saving on the amount of land needed and dramatically reducing the number of travel and turning lanes.

All roundabouts in the county have crosswalks and are typically single-lane, with island refuges, or splitters, used to minimize the amount of traffic one has to negotiate on foot. Runge says he isn't aware of many pedestrian accidents in multilane roundabouts, either.

"The roundabouts tend to fit with our land-use recommendations," says Chuck Lamine, AICP, Brown County's planning director. "They prevent the county from having to build a bigger road, because the two-lane roundabout can accommodate as much traffic as a four-lane road with signals." He noted that in some cases towns and villages have located public buildings at the roundabouts, using them as gateways and transition points from highspeed roads to more residential streets.

Taming highway transitions

That transition from highway to an urbanized street pattern was part of the challenge for Durango, Colorado (pop. 17,834), when it decided to build a displaced left turn or continuous-flow intersection. The project was chosen to improve the meeting point of U.S. routes 160 and 550, along the Animas River and just outside the downtown. Both are major roads serving southwestern Colorado and carry heavy traffic year-round, but especially in summer when tourists flock to the area.

In recent years, traffic began to back up at the intersection and at College Drive, a four-way corner just to the north that is used by drivers, pedestrians, and cyclists to move in and out of downtown. Years ago, the Colorado Department of Transportation had proposed building a cloverleaf to ease traffic flow. But the state and city had made multimodal access a key part of planning for road projects, and the good old cloverleaf just didn't seem like the right fit.

The CFI, built in 2014 after an extensive public process to calm people's fears of the unknown, allows motorists to drive in both directions through the main part of the intersection without stopping for a signal. Left-turning drivers move into a dedicated lane for that purpose well before they get to a traffic light.

A stoplight is necessary for drivers to cross oncoming traffic, of course, but because it's located well before the rest of the intersection, it doesn't slow things down much. "Given the configuration of the existing roadways, I'm astounded it works," says Greg Hoch, Durango's community development director. "It's on a curve, so you don't have full visual sightlines."

The novel intersection was paired with significant urban-style improvements for cyclists, including bike lanes and bike boxes. A dedicated signal phase allows cyclists to negotiate the multiple lanes of traffic. "The goal is for a seventh grade-aged child to be able to move through Durango comfortably," says Amber Blake, a Durango city planner.

However, pedestrians generally avoid the intersection, since there is a walking path along the river that parallels one of the two highways, giving them a more pleasant — and vehicle-free — route.

It is too early to have concrete data showing how much safer the Durango CFI is than the intersection it replaced. A similar intersection built in Salt Lake County, Utah, saw a 60 percent drop in crashes, according to a study by the Federal Highway Administration.

Tommy Humphrey, a city engineer who helped design the improvements, says that he has heard anecdotally that motorists are slowing down sooner as they approach the intersection, perhaps because of the early left turn lane. The time people wait at the intersection has definitely decreased, says Blake.

Superstreets soften busy crossings

Holly Springs (pop. 30,157), a suburb of Raleigh, North Carolina, took a different approach to managing congestion and making intersections safer along Highway 55, a bypass that carries through and local traffic around town, with a speed limit of 55 mph. The town chose in 2013 to build five restricted crossing U-turns, otherwise known among engineers as superstreets. All were retrofits of existing intersections in response to development of a large commercial site along the road.

When a motorist enters one of these intersections from the minor street, she cannot drive straight across or turn left. Instead, she is forced to turn right and travel a significant distance out of the way, then make a U-turn. Though it appears at first to be an inconvenience, the design allows these drivers to avoid a traffic signal altogether, saving time and reducing the number of potential leftturn collisions. Since there are relatively few turning movements in the intersection, those who are turning left off of the major street wait a much shorter time for the light to turn green than they otherwise would.

Medians in each intersection provide a refuge for pedestrians and cyclists, much like in a roundabout. Since there is no vehicle travel directly across the highway, the medians extend the length of the intersection. There are also pedestrian signals at each superstreet. Cyclists have the option to cross the road like pedestrians would, or they can travel with cars and make the U-turn.

A 2011 study by North Carolina State University showed that superstreets see a 20 percent overall reduction in travel time compared to similar intersections that use conventional traffic designs. The intersections also experience an average of 46 percent fewer reported crashes, and 63 percent fewer crashes that result in personal injury.

"For some people that travel along the less used routes the project wasn't as well received," says Aaron Levitt, an engineer for Holly Springs. "People seem to be getting used to the new intersections, although there are still some naysayers."

Road patterns. Graphic by David Foster.

The devil's in the (diverging) details

Another unusual road design intended to ease congestion and reduce accidents for drivers and people on bikes or on foot is the diverging diamond intersection. This odd concept forces drivers to move, like the British, to the left side of the road, which is why the design has captured the fancy of engineers and planners alike. It also works well from a practical standpoint, and there are now over 60 such intersections around the U.S., all built since 2009.

Unlike roundabouts, displaced left turn intersections, or superstreets, diverging diamonds are usually built over interstates and other limited-access expressways. The expectations for pedestrian and bicycle access and comfort are particularly limited in these environments. Nevertheless, in some cases engineers have tried to make them feel safe for everyone.

The first one, built in Springfield, Missouri (pop. 165,378), on U.S. Route 13 over Interstate 44 in 2009, features a pedestrian/bike path running through the middle of the highway overpass, with pedestrian lights and crosswalks at each end of the intersection. Average speeds where motorists might cross the path of pedestrians are 20 to 35 miles per hour, compared to 40 to 50 mph in a more conventional highway interchange, says David Hutchison, a bicycle and pedestrian engineer for the city.

But the project earned the ire of Charles Marohn, AICP, the creator of the Strong Towns website and a strong critic of how state transportation agencies tend to design roads. "Cyclists are selling themselves short if they view this project as a success," he says in a voiceover he narrated of a video about the project and posted on his website. "Yes, they did accommodate cyclists, but this is not conducive to a society that is going to embrace cycling. This is better than what we would normally get, but I don't think any driver would expect a pedestrian in this place. It's not designed for pedestrians."

The project did reduce accidents at the intersection by 50 percent, according to data from the city's public works department.

"Few freeway interchange designs are comfortable for people that are walking and bicycling," says Hutchison. This design is an improvement. "The diverging diamond provides more control and lower speeds for walkway crossings," he says, while admitting that the dedicated path through the overpass feels "like walking in a canyon surrounded by large, loud motor vehicle traffic."

The bigger selling point of diverging diamonds is how much money they can save. The first one in Springfield cost $3 million, compared to the $10 million a more conventional redesign of the intersection would have cost. The city has since built five more diverging diamonds.

David Holtzman is a writer in Louisa County, Virginia.

Watch

Roundabout

All About Wisconsin Roundabouts: tinyurl.com/neet8gl

Displaced Left Turn or Continuous Flow

Displaced Left Turn Case Study, Bangerter Highway in Salt Lake County (Utah): tinyurl.com/jv5x9dg

Diverging Diamond

Diverging Diamond Animation: tinyurl.com/okuo9oq

Best of Blog: The Diverging Diamond: A skeptic doubts bikes and pedestrians will benefit from this configuration: tinyurl.com/cx73r2t

Bringing Safety — for All Users — to a Tribal Community

By Jeff Schwein, AICP CTP

In rural areas, it's hard to base the value of a project on the number of users. But in the remote canyons of the Klamath River in northwest California, a tribal group used qualitative data to help bring safety and connectivity to the people who asked for it.

The people of the Karuk Tribe live in the Douglas fir and redwood forests of northern California and southern Oregon. Most of the population lives in close proximity to the most valued cultural resource: the Klamath River and its Chinook salmon.

Red Cap Road's hazardous conditions before the project. Photo by Josh Wolf.

A new bike lane, guard rail, and bank stabilization. Photo by Josh Wolf.

The finished project. All photos show west-facing views; the Klamath River is on the right. Photo by Josh Wolf.

The low-income community of Orleans, California (pop. 900), is nestled on the banks of the Klamath River and is served by State Route 96. Like many rural communities, the residential areas spread outward from the commercial core and the transportation network was developed for cars, not people.

On the opposite side of the river and connected by a bridge, Red Cap Road is about 1.5 miles long and connects 20 percent of the Orleans population with the community core and major highways. The route is particularly important to tribal members of the community, as it provides access to many ancestral tribal sites and the tribal housing development Shivshaneen.

The road was once seen as dangerous, but that's changed. In the fall of 2015, the Red Cap Road Bicycle and Pedestrian Safety Project opened, thanks to a successful campaign led by the Karuk Tribe Department of Transportation.

Red Cap Road is narrow and winding with little to no shoulder on either side, yet is commonly used by bicyclists and pedestrians for primary access. This dangerous combination is exacerbated during rainy and low light conditions. Planners, however, lacked the substantive crash data to tell the story.

But with creative planning and outreach, the Karuk Tribe, in partnership with the Humboldt County, Caltrans, and the Humboldt County Association of Governments, was able to develop a competitive project and secured $2.75 million through various programs to complete it.

With limited quantitative accident data, the project development team gathered compelling anecdotal evidence from community members, including information on critical injury accidents and historic fatalities. In 2013 the Karuk Tribe was awarded a community-based planning grant and prepared the Middle Klamath River Community Transportation Plan, which initially identified the problem.

With a solid planning foundation, the tribe and county public works department secured funding for environmental and design work through the Transportation Enhancement program, which they leveraged with funds from the Federal Highway Administration's Highway Bridge Program and California's Toll Credit program. Finally, the Karuk Tribe received a federal Tribal Transportation Safety Program grant of $872,000, the largest in the nation, in 2014.

The Red Cap Road Bicycle and Pedestrian Improvement project was simple enough: It widened shoulders and a bridge, improved signs and striping, and realigned a dangerous "S" curve.

But it was not without challenges. Multiple threatened and endangered species in the area (particularly anadromous salmonids), Native American cultural sites, and project design constraints (including unstable geology and steep slopes) put program and project managers to the test.

But in the end, persistence paid off, and today the people of Orleans can feel safer on this rural roadway.

Jeff Schwein is president of Green DOT Transportation Solutions, a planning firm based in Chico, California, that developed the initial transportation plan and helped secure funding for the project.