This interview is part of a bi-weekly series with sustainable transportation advocates, planners, engineers, journalists, sociologists, and other experts working to shed light on best practices and solutions from across the globe. We welcome your suggestions for future Q&As.

Arlington County Board Vice-Chairman Christopher Zimmerman has been a long-time advocate of transit-oriented development (TOD) and managed growth for the Washington, D.C. region. The county he represents is known for its dense development concentrated around transit stations, including Metrorail. In 2002, Arlington County received the U.S. Environmental Protection Agency’s National Award for Smart Growth Achievement for “Overall Excellence in Smart Growth.”

In a surprising and unexpected announcement yesterday, Zimmerman resigned  from his role as Arlington’s representative on the Washington Metropolitan Area Transit Authority (WMATA) Board of Directors, for which he has served since 1998, and said he will assume the Chairmanship of the Arlington County Board on January 1. He will continue to serve on the Northern Virginia Transportation Commission (the governing body for WMATA in Virginia), as well as on the Transportation Planning Board for the National Capital Region, and the Northern Virginia Transportation Authority.

“My commitment to transit and to Metro is as strong as ever,” he wrote in a letter, “and I will continue to work for improvements to rail, bus, and paratransit services in our region.”

Zimmerman, who served as a panelist at a recent “Cities in Focus” event hosted by EMBARQ (the producer of this blog), talks to us about the opportunities and challenges of “New Urbanism” in the suburban region.

What have you done to improve pedestrian conditions in Arlington?

Building new sidewalks has been hugely important, as well as improving the intersections through efforts like curb extensions, which provide pedestrians a shorter crossing distance. These designs make cars more visible for pedestrians and pedestrians more visible for cars.

You also have to calm traffic, which basically means making traffic slower. This can be as simple as how you lay down paint or putting in bike lanes, which helps to narrow the visual appearance of the street and make drivers more cautious. A variety of changes make the environment more conducive to pedestrians. Street furniture and benches communicate an atmosphere for pedestrians. If people see there’s a place to walk, then more people walk. For example, lighting matters: lower and more attractive street lights provide better lighting for pedestrians. Previous lighting in Arlington was designed for cars. Also, street trees increase separation between pedestrians and moving traffic and making walking more comfortable in the summer. And people driving on a street with trees drive slower. Also, on-street parking acts as a barrier between pedestrians and moving traffic.

Why do trees make people drive slower?

Any kind of vertical element will narrow the visual field and cause people to drive slower. In fact, highway departments tend to take such elements out of their designs because they are viewed as a hazard to the car and highway agencies tend to accommodate high-speed and high-volume traffic. The presence of those things makes drivers more conscience of their surrounding.

How are you building affordable and livable communities in Arlington?

There is a substantial proportion of Arlington that is low- to moderate-income. There are many for whom public transport is a necessity. However, it is also true that a large portion of higher-income Arlington residents want to use public transport.

A lot of people have come here because they don’t want to use a car and want to have a lifestyle that is more transit-oriented. We created the ART bus system almost 10 years ago.  It has grown tremendously and extended the reach of Metro, reducing traffic and pollution in neighborhoods. We’re trying to increase ridership by providing reliable and friendly public transit. The buses use clean natural gas (CNG) and are smaller than your typical bus. They have become familiar and something people recognize. People have been very quick to demand extension in terms of where the lines would reach and hours they would run. We’ve been expanding pretty much every year. For example, we’ve extended the bus service between Shirlington Village and Ballston. This extension was really demanded by the community. One of the most advanced bus centers in the region is Shirlington. The systems connect you to various Metro stations in various parts of the county, providing alternatives and options for people.

In such a high-income area, how do you ensure that the cost of living does not continue to rise and the area supports access to transportation among broad income levels?

The biggest challenge for us has been providing affordable housing in the area. We have very little competition because there aren’t enough areas to meet the demand for TOD. The consequence is that rents and housing costs rise.

In Arlington we have a very extensive affordable housing program. We’ve created about 6,000 units, 14 percent of the county’s housing, for affordable housing for people living at 60 percent or below median income. We do this through a revolving loan program for new construction, a housing grants fund, contributions from high-value development to affordable housing and partnerships with non-profits.

Currently we have a project on public land where we are building a community center in an abandoned grocery center. There will be a new apartment building with affordable units called Arlington Mill.

To what to extent do the counties in the region work together?

Quite a lot. It is extremely important because you can’t have transportation solutions without regional cooperation. One success has been Metro. For 40 years, the system has carried over a million people a day.

Within Virginia, we have strong cooperation among the jurisdictions. What we’re trying to do now is have a regional bus priority network, which will use a variety of approaches to provide right-of-way for buses. The streets are controlled by states and municipalities, so in order to have a continuous network, you must have cooperation.  Also, bus lines run across different jurisdictions – you have to coordinate and agree on how bus routes will run.

Metro itself works by bringing together the different governments. All the jurisdictions in the area have representation on the board; every meeting is a meeting of different regional governments. We also have jurisdictions working on the staff level as a committee to coordinate things ahead of board action, where a lot of important work gets done communicating between WMATA and various governments. For example, the Dulles Corridor Metrorail Project (a 23-mile extension of Metrorail to Dulles Airport in Virginia that will include 11 stops) involved the cooperation and input of different governments across counties.

In Montgomery County, Md., a serious issue is the lack of parking at Metro stations. Is this an issue in Arlington?

This is not really an issue in Arlington given the walkability of the area. Shirlington is the only stop with a large area for parking.  Most people connect to transit through buses or walking. If a bus is going to be a sure alternative, then you have to make it as regular and reliable as rail service. If people have to wait 12 minutes for a train, they complain, but that’s the best bus service you can get in this region. You have to have very regular service for people to use it. People won’t use it unless they know it will show up.

Buses became really unattractive and they were considered an option for poor people. People need to know that buses are for everybody. They should be convenient and attractive and have lower floors for easy boarding as well as waiting areas and information. One of the most important things we’ve done is provide real-time information for bus users.  Knowing that you can really plan what you’re doing and that the bus is as an option over the car is essential.  In Fairfax County [next to Arlington County], most people drive to the Metro. However, with the strain on parking, people are starting to get use car shares and take Metrobus. Residents also use the Fairfax Connector to transfer onto rail.

What do you see as the future of bus in the region?

In Arlington, we would like to see continued expansion of bus services to seven days a week. We only have some weekend service now. We’ve got to rachet up both the frequency and span of the service. We are getting there incrementally.

On the regional level, we need bus priority that can get through traffic. Even if highway expansion would work, it’s not being done. We need dedicated lanes for buses so people can get downtown at regular intervals.  It is more efficient to move more people by bus and can greatly reduce congestion with only a small expansion of bus services.

Rail isn’t going to go everywhere because people made bad choices about Metro planning so it is going to take a long time to get a better land use pattern in the region. If we do everything right for the next 30 years, it still won’t be much better and there will still be regions non-accessible to rail. So we have to find ways to connect places that aren’t on the rail system. We have to use the existing road infrastructure to supplement a rail system that will never be sufficient to move everybody around the region.