Ambulances in DC generally take longer to respond to neighborhoods east of the Anacostia River, and the river itself seems to be part of the cause. This map, which I made using data obtained from DC FEMS under the Freedom of Information Act, shows areas of the city where the proportion of all critical 911 calls where an ambulance took more than 10 minutes to arrive at the scene from the time they were notified.

Graphic by the author, with data from DCFEMS.

When Julette Saussy, the former head of emergency medical services for DC, resigned last February, she wrote an open letter to the city explaining her reasons. In the letter she mentions Robert Leroi Wiggins, a 35-year-old man stabbed in the Benning Ridge neighborhood on January 27, 2016. After 18 minutes, an ambulance finally arrived and transported Mr. Wiggins to a hospital. Four days later, he succumbed to his injuries. Ms. Saussy suggests that he might have survived if the ambulance had reached him sooner.

Tragic stories like Mr. Wiggins’ are not unheard of. In September 2015, a 5-month old baby stopped breathing, but the nearest ambulance was over seven miles away, and in March 2016, a gunshot victim waited over 30 minutes for an ambulance.

A disproportionate number of these stories seem occur in neighborhoods east of the Anacostia River.

Response times are quick close to DC’s core, and particularly slow in Ward 7

Three anecdotes do not constitute a trend, but according to the data, ambulances responding to critical 911 calls east of the Anacostia seem to have difficulty meeting the city’s own standards for ambulance response times.

DC’s contract with the private ambulance company, American Medical Response (AMR), stipulates that the company is expected to respond to 90% of all calls in less than 10 minutes. Applying this standard on a per-neighborhood basis allows us to see where response times are adequate and where they are not.

Take a look at the map above. Areas that tend to meet the 10%-or-less standard are clustered around the center of the city, near the preponderance of DC’s medical facilities and high-speed travel corridors. Areas east of the Anacostia fare much worse, particularly from about noon to the early evening and in Ward 7 neighborhoods at the eastern edge of the city.

There are fewer medical resources in the eastern parts of the District

According to Andrew Beaton of DC FEMS, this is the result of busy ambulances accumulating in the western portion of the city.

“The greatest number of EMS calls resulting in patient transport are heavily concentrated in the center of the District and, to a lesser degree, in two areas south of the Anacostia River,” Beaton said.

“Response times during the day are affected by traffic and pedestrian density, especially at intersection choke points, reducing the mobility of ambulances and resulting in average response speeds of 15 miles per hour or less. The Anacostia River and Interstate 295 also represent geographic barriers difficult to overcome many times during the day. When combined with high call volume— especially unpredictable surges— this can result in longer ambulance response times in the southern areas of the District. “

Traffic on bridges across the Anacostia— a problem recent infrastructure changes have exacerbated— and a complete lack of trauma centers east of the Anacostia creates a recurring situation where ambulances struggle to reach patients.

Mr. Beaton indicates that since the contract with AMR started, response times have fallen city-wide. Any improvement is good, but increasing the number of ambulances on the road and augmenting FEMS resources are short-term improvements. They do not address the underlying structural issues: the chokepoint across the bridge and the dearth of trauma centers east of the Anacostia .