Through-traffic doesn't belong downtown.

Before Ghent redrew its centre in 2017, the city counted the cars and found that nearly 40 percent of them had no destination inside it. Groningen made the same discovery in 1977: when it blocked the shortcut, car traffic in the centre fell by almost half, while the share of people who drove to the centre barely moved. The cars that vanished were the ones passing through.

Stad Gent, The Circulation Plan; Tsubohara, University of Groningen, on the 1977 plan.

Nearly one office in four downtown stood empty at the end of 2025, twice the rate of the decade before the pandemic. Office attendance is about half what it was. The District's answer is to make downtown a place people live: 15,000 new residents by 2028, most of them in converted office buildings. The downtown BID now dates that goal to 2033 and says that even if every announced conversion is built, the count reaches about 40 percent of it. Residents, shoppers and diners are the customers now. The cars crossing downtown on Constitution Avenue at 5 pm carry none of them.

DowntownDC BID, State of Downtown 2025; Mayor's Comeback Plan, January 2023.

Ghent redrew its centre in April 2017. The city's evaluation a year later counted new shops and restaurants in the central postcode up 20 percent, closures and bankruptcies down 7 percent, and the centre growing faster than the rest of the city. Madrid saw the same thing when it closed its centre to through-traffic in late 2018: card spending that Christmas rose 8.6 percent inside the zone against 3.3 percent in the rest of the city.

Stad Gent and Transport & Mobility Leuven, Evaluatie Circulatieplan Gent, 2019; Ayuntamiento de Madrid analysis of 20 million BBVA card transactions, January 2019. Madrid's retail lobby disputed the city's figure with a survey of its members.

Since 2016 Oslo has removed about 760 street parking spaces inside its inner ring, most of them in 2017 and 2018, and filled the space with benches, bike lanes and terraces. Traffic in the centre fell. Pedestrian counts rose 14 percent, and the number of people sitting, standing and lingering in the central squares rose 43 percent. In 2019 not one pedestrian or cyclist died on an Oslo street.

Sweco for Oslo kommune, Bylivsevaluering 2019. The same evaluation found shop turnover in the centre grew at the same pace as the rest of Oslo in 2018.

Measured across the whole streetscape, more than three-quarters of New York's street space is travel lane or parking. Sidewalks get less than a quarter. Paris gives half its public space to motor vehicles that carry 13 percent of its trips. Washington has not published the split for its own downtown, but the counts say what the lanes are for: 120,000 vehicles a day pass under the Mall in the I-395 tunnel, and 29,500 cross downtown on Constitution Avenue between 12th and 14th.

Transportation Alternatives, NYC 25x25 (2021); Le Monde on Paris public space (2016); DDOT 2024 traffic volume counts.

When the block of Pennsylvania Avenue in front of the White House closed in 1995, the avenue stopped working as a route across downtown. DDOT's own 2018 study found that drivers now use it for a few blocks and turn off, leaving "excess capacity and an opportunity to repurpose roadway space." This spring the National Capital Planning Commission put out three designs that cut the avenue from eight lanes to four between 3rd and 13th Street. Take the through-route away and the lanes were never needed.

DDOT and NCPC, Pennsylvania Avenue East of the White House Transportation Study, 2018; NCPC design concepts, April 2026.