Gordon Chaffin is a freelance journalist who focuses on infrastructure and traffic news and insights for Street Justice. You can support independent journalism by subscribing to Gordon’s newsletter. He’s offering a 20% discount to THIH readers. –Maria Helena Carey
What is “Traffic Calming?”
Many of the transportation projects we cover in Street Justice involve something called Traffic Calming. What’s that? Well, it’s street design to slow motorists down. Why slow cars down? Vehicle speed is the most important contributing variable to the physical damage from a crash. The higher the speed, the more likely damage is serious or fatal — and the relationship is exponential.
A lot of this research comes from Europe and the metric system is objectively better, but that x-axis converts to 6, 13, 19, 25, 31, 38, 44, 50, 56, 63, 69, and 75 mph for 10, 20, 30, etc kph. Those charts show the probability of fatality for the average pedestrian. However, and this is key, those likelihoods of fatality shift significantly when demographic variables change.
Sources for the above three image can be found here.
The three graphs above show important differences in the fatality rate by age. At slow car speeds, 10-15 mph, almost no crash victim is killed. At highway speeds, 55 mph or more, a driver hitting a pedestrian will almost always kill them, regardless of victim demographics. The zone between 20 mph and 55 mph — the vast majority of urban and suburban driving — there are large differences in the fatality of car strikes by victim demographics. Crash data show that traffic deaths skew older. It’s the senior citizen crossing Columbia Pike in Arlington, VA, struck by a driver going 47 (it’s 30 mph limited, but the Pike’s design induces much higher speeds.
To make streets safer for pedestrians and cyclists — and for motorists where higher speeds mean likelier death behind the wheel — transportation officials introduce traffic calming concepts. Some traffic calming implements are physical — narrowing and/or car travel lanes — and other calming is psychological/behavioral. The latter is often just as important as the former.
The National Association of City Transportation Officials (NACTO) has a lot of great information about speed management strategies and traffic calming tactics. In addition to the facilities below, adding bike lanes and bus lanes are traffic calming measures.
Image source here.
Most citizens aren’t familiar with the wide variety of physical and psychological street safety concepts. Most residents, when they show up to a public meeting or talk with a local government staffer, only know of speed bumps. As you discuss transportation projects and challenges with your family members, friends, co-workers, and neighbors, it’s important to listen to their safety concerns. Those concerns are often on the same page with your desire for wider sidewalks, better bike lanes, and vehicle lanes converted to bus lanes.
Safer streets require slower speeds on roads that get used by commuters, by busy parents shuttling their kids and running errands. Projects like Alexandria’s Seminary Road debate became huge fights about delaying car commuters, diverting the impatient among them to parallel residential streets. But, if nearly everyone, thinks their local roads need to be safer, and data say slower speeds are safer, then this is really a conversation about priorities. X minutes of delay, Y% slower speeds, for less fatal crashes.
Government staff and their contractors often produce traffic studies saying reduced car travel lanes cause several minutes of increased vehicle delay in the project area. But those reduced speeds are safer. When drivers, pedestrians, and cyclists make mistakes — and all of them do, every day, hour, and minute, across the Washington region — lower speeds mean fewer people die. As every DC-area locality takes on the Vision Zero goal — nobody dies in our streets — it’s important to remember that aim as *not about behavioral approbation*. It’s fine to have public safety campaigns for driving slower or crossing the street after looking both ways. But, that’s not Vision Zero. VZ is about re-designing bureaucratic and physical infrastructure so that the systems of travel don’t set up potentially lethal situations when mistakes happen.
The automobile special interest AAA has a galaxy brain opinion that re-designing roads to lower car speeds and delay drivers means those motorists will act out in rage-filled defiance. This is why the car lobbying group opposes banning right turns on red in Washington, DC. There are no data to support this claim.
Moreover, it’s revealing the logic of that counter-argument includes the premise that motorists are driving dangerous things that can become weapons when their users get angry. For an organization that claims to work for traffic safety, it’s instructive that their warning messages to elected officials present veiled threats: be careful, don’t make drivers too angry, they might hurt someone acting in childish defiance behind the wheel of their hybrid SUV equipped with Honda Pro-Pilot Safety360 Automatic Emergency Driver Assist Lane Keep Rear Cross-traffic Alert.
Imagine if bicycling groups warned public officials that insufficient bike lanes or inconveniently located trail connections meant high-visibility wearing bike commuters would start intentionally running over pedestrians with their 15-pound bikes. Imagine if pedestrian safety groups told County Commissioners the lack of a crosswalk signal meant seniors would link arms and block traffic on East-West Highway, voicing passive-aggressive comments about motorist outfit choices.
DC’s Brookland Getting Pick-Up/Drop-Off Zone
In the next few months, DDOT plans to install a Pick-Up/Drop-Off (PUDO) zone on the 600 Block of Monroe Street NE — the Edgewood/Brookland neighborhood, ANC 5E01. This block features mixed-use residential buildings with ground-floor retail within a 5-minute walk of the Brookland/CUA Metrorail station. The location is heavily populated with students from Catholic University, whose campus is adjacent
In 2017, DDOT created nightlife PUDO zones in Dupont Circle. In 2018, DDOT created full-time PUDO/delivery zones in commercial hotspots: 14th Street NW, the National Mall, the Wharf, Georgetown, and Union Market. In 2019, DDOT expanded with additional PUDO spots in those neighborhoods and expanded to Barrack’s Row, H Street NE, and the Navy Yard. DDOT has created 18 PUDO spots in the last three years, which data show are successful interventions, but none in Ward 5.
Montgomery County Leaders Call for Restored Bus Rapid Transit, But Show Internal Division
On Monday morning, leaders from Montgomery County put on a press conference calling for the restoration of state funding to the Corridor Cities Transitway (CCT), a bus rapid transit project in “up county” MoCo. In September, the Maryland Department of Transportation cut the CCT from its Consolidated Transportation Plan running from 2020-25. The CTP is a medium-range capital budgeting document. The cut means Governor Hogan and MDOT head Rahn do not intend to move forward with the project.
DC Bike & Pedestrian Advisories Press DDOT Director Jeff Marootian
Monday night, DC Department of Transportation Director Jeff Marootian joined the DC Bike and Pedestrian Advisory Councils for a Q&A session that lasted almost two hours. The two advisory groups meet separately most months and jointly once or twice per year for big issues or speakers on topics of common concern. Along with Marootian, came DDOT’s new Cheif Project Delivery Officer Ellen Jones, Associate Director for the Planning and Sustainability Division Jim Sebastian, Active Transportation Branch Manager George Branyan, and Vision Zero team wunderkind Emily Dalphy. Only one DDOT staff member joins most BAC and PAC meetings. Marootian used his staff to answer questions on specific programs and projects where he doesn’t have the most detailed or latest information.