​WASHINGTON, D.C. ― The NTT IndyCar Freedom 250 race around the National mall was one of the most electric races in the history of American motorsport. Like the Indianapolis 500 on Memorial Day weekend, it was a stage unlike any other ― its trophy coveted by drivers and teams.In execution, however, D.C.’s street race celebrating the nation’s 250th birthday was similar to Penske Entertainment’s annual home race, the Detroit Grand Prix.The traveling IndyCar circus is the world’s most challenging race series because it tests drivers (and organizers) on venues from 240-mph ovals to writhing road courses to gritty street courses.  This year, IndyCar had five urban slugfests on its 18-race calendar: St. Petersburg, Florida; Long Beach, California; Markham, Ontario; Detroit and D.C.The latter pair have the most in common. “The track is a lot like Detroit, actually,” said Indy 500 winner and Andretti Global ace Marcus Ericsson in a trackside D.C. interview. “Very bumpy with a long front straight that is the best spot to pass.”A comparison of the unlikely fraternal twins:The backdropsBoth the Freedom 250 and Detroit GP are very aware of their optics. Detroit is built around the Renaissance Center, one of the most imposing, recognizable skyscrapers in North America.The Freedom 250 layout was originally supposed to take place on Capitol Hill between the Capitol nuilding and the Supreme Court on 1st Street. Politics nixed that and organizers settled for the National Mall. The backdrop was still extraordinary: Turn One with a Capitol backdropPits off Pennsylvania Avenue main straightaway in front of the National Gallery of ArtTurns 2 and 3 splitting the National Archives and the Department of Justice. Back straight on Independence Avenue in the shadow of the Air & Space Museum’s three monolithic facades.“Jumping into the car on pit lane and looking down at the Capitol, its spectacular,” said Ericsson. “Super cool, and for our sport a ginormous opportunity for us to reach new fans.”Both venues demanded unique logistics.Running ‘round RenCen means the Detroit GP has to keep an international border crossing open. For three days, vehicles continue to cross between the United States and Canada via the Detroit-Windsor Tunned. Emerge from Canada and head east on Jefferson Avenue going 35 mph. In the westbound lanes? IndyCars doing 180.Washington’s patchwork of federal land, city streets and historic buildings meant that Penske Entertainment had to get a staggering 1,350 permits approved.The tracksBoth circuits are 1.7 miles long. On gridded streets with 90-degree turns and little elevation change. Detroit requires sealing 162 manhole covers (lest IndyCars’ aerodynamics suck them out of the ground). The D.C. track? 200 covers were secured. Chip Ganassi Racing star Alex Palou won pole in Detroit this summer with a lap time of 1.01.9 minutes (96 mph average speed). Palou won pole in D.C. with a lap time of 56.9 seconds (108 mph