From the mid-1970s, when Metro was born, through 2008, the agency bought six batches of rail cars, a total of 1,134 cars, nearly all of which are still in service. The oldest, the 1000-series, dates to the opening of the subway, and newest, 6000-series, arrived a decade ago. Notice how all the cars more or less look the same, regardless of age? That’s because Metro wanted aesthetic consistency. It also wanted each new batch to be mechanically similar to the batches that came before, so that cars of different ages could be coupled together in trains. But maintaining mechanical compatibility meant limiting technological upgrades as each new batch came off the assembly line.

Now, finally, Metro is about to begin phasing out the old cars in favor of a new generation, the 7000-series. These cars are so advanced, they will run together as separate trains, never coupling with the current fleet. Sixty-four of the new 7K cars are due to be in service by summer 2015, and 748 by 2018. One set of four 7K cars has been undergoing tests on Metro tracks since the start of the year. Tuesday morning, we went along for a ride.

Test riding a new 7000-series Metro rail car shortly. Lots of pix coming of the many wonders awaiting me this day. http://t.co/oHuS2foVhl — Paul Duggan (@dugganwapo) May 20, 2014

64 new 7Ks due in service by 7/2015; 748 by 2018; $2B cost; 400 old cars, most ’70s vintage, to be scrapped. pic.twitter.com/tvzoV8LxIR — Paul Duggan (@dugganwapo) May 20, 2014

Out: Dull brushed-aluminum frame w/ chocolate stripe. In: Gleaming stainless steel w/ black-white logo. pic.twitter.com/8CEqHcg34t — Paul Duggan (@dugganwapo) May 20, 2014

7Ks so advanced, they’re incompatible w/ current fleet; will run as separate trains, never coupled w/ older cars. pic.twitter.com/Bg6dKdo9nZ — Paul Duggan (@dugganwapo) May 20, 2014

G’bye disco-era earth tones and squeeze-in-fatso armrests. Hello cool blues, more handrails. (Weight for brake test) pic.twitter.com/6AZe3X7TGs — Paul Duggan (@dugganwapo) May 20, 2014

Yo, train nerds. I’m gonna tweet a long-ago quote. See if you know who said it. Okay? Here it comes … — Paul Duggan (@dugganwapo) May 20, 2014

“Take the roughest man … into a room elegantly carpeted … and the effect on his bearing is pronounced and immediate.” … Says who? — Paul Duggan (@dugganwapo) May 20, 2014

A: George Pullman, inventor of the luxury rail car. Since the ’70s, Metro carpeted its cars to give long-haul commuters a sense of comfort. — Paul Duggan (@dugganwapo) May 20, 2014

But carpet stains are hard to get out. 7Ks have smooth “Reslient” floors, easy to clean. Here still under plastic. pic.twitter.com/FcTPdmCKDd — Paul Duggan (@dugganwapo) May 20, 2014

No more neck-craning to see station signs. Board shows where you are, where you’ve been, where you’re headed. pic.twitter.com/4omDtg2vO1 — Paul Duggan (@dugganwapo) May 20, 2014

On 7Ks, being built in Nebraska by Kawasaki, higher-tech doors won’t be balky and make you insane, Metro swears. pic.twitter.com/wIA1yQYfUB — Paul Duggan (@dugganwapo) May 20, 2014

This fella here is in charge of it all, Devo Ogunrinde, Metro senior project manager for rail car engineering. pic.twitter.com/woVfTe5zfr — Paul Duggan (@dugganwapo) May 20, 2014

No! You can’t ride yet! Important media people only! Please step back! pic.twitter.com/eEuj4VuRHn — Paul Duggan (@dugganwapo) May 20, 2014

Cruising 75mph, smooth! Came upon this while strolling train. Won’t know what it is till I push it, see what happens. pic.twitter.com/1GjmqQmhBK — Paul Duggan (@dugganwapo) May 20, 2014

No overhead rail in the doorway. So you got nothing to grab. So you’ll … MOVE TO THE CENTER OF THE CAR … pic.twitter.com/sbluXNSjTr — Paul Duggan (@dugganwapo) May 20, 2014

Lastly: 7Ks more “crashworthy,” more energy-efficient, more rider-friendly, Metro promises. Techies doing tech stuff: pic.twitter.com/sOs6KEVlPI — Paul Duggan (@dugganwapo) May 20, 2014

Well, that was fun. Sorta like Kings Dominion for transit nerds. … Bye-bye, choo-choo! pic.twitter.com/l3USPPIFrN — Paul Duggan (@dugganwapo) May 20, 2014