The “clang-clang” sound may be a digital sample, but the streetcar itself is — finally — the real thing.

Originally intended to debut last spring, the long-delayed Atlanta Streetcar will make its maiden voyage Tuesday, Dec. 30 on a 2.7-mile loop of track through downtown Atlanta.

Atlantans haven’t hopped on streetcars since 1949. Here’s a primer, a Streetcar 101, for newbies.

Stops:

The Atlanta Streetcar travels a 2.7-mile loop from Centennial Olympic Park in the northwest to the Martin Luther King Jr. National Historic Site in the east. There are 12 stops along the way, at places including Peachtree Center, Woodruff Park and the Sweet Auburn Market. Streetcars only pick up and discharge passengers at designated stops.

Cost:

For the first three months there will be no charge to ride the streetcar. Thereafter patrons will be charged $1 a ride.

Times:

The streetcar will run 6 a.m. to 11 p.m. Mondays through Thursdays; 6 a.m. to 1 a.m. Fridays; 8:30 a.m. to 1 a.m. Saturdays and 9 a.m. to 11 p.m. Sundays.

Getting on and off:

The streetcars offer “low-floor” access, so that wheelchairs and other assisted devices can roll directly on board.

Should you walk or ride?

Two streetcars will be operating at all times. The vehicles will make the one-way trip in about 9.9 minutes, and will arrive at stops about every 15 minutes. The average person can walk the one-way route in about 26 minutes, so if you miss one vehicle and the next car isn’t coming for 15 minutes, it might make sense to walk.

Sharing the road with streetcars:

During testing the streetcars were involved twice in collisions with motor vehicles. In both cases the drivers of the motor vehicles were cited.

“People get impatient and think they can beat a streetcar,” said former spokesperson Sharon Gavin. She added that Atlanta drivers will have to learn how to interact with streetcars, and it will be an ongoing challenge.

“In Portland they have 45 incidents a year and they’ve had streetcars for 10 years,” she said. “There will always be a learning curve, which is why our education and outreach program will be here to stay.”

The cars weigh 48 tons, and when traveling 20 mph require 60 feet to come to a stop. Streetcar personnel stress that trying to pass a streetcar is a mistake.

On the other hand, cars can drive on roads that have streetcar tracks on them. Bicyclists should try to cross the streetcar tracks at right angles to avoid having a wheel snared.

Streetcar etiquette:

The rules of behavior on the streetcar are the same as those on MARTA trains and buses. Smoking is prohibited, as are open containers of food or drink. The streetcar website says: “No shirt, no shoes – you know the rest.”

The city is spreading news of the streetcars through various channels, including YouTube videos featuring standup comic Jessica “It’s All Good” Williams.

Streetcar facts:

There are four cars. Each is 80 feet long, 9 feet wide and 12 feet high. Each has seating for 60 including designated spots for four wheelchairs. In a pinch the streetcars can carry 200 passengers, most of them standing. “You’re not smushed up against each other, but you all fit in,” said Gavin.

The streetcars are manufactured by the German company Siemens. The bodies of the vehicles were built in Sacramento, Calif., and the propulsion systems were constructed in Alpharetta. They run off of DC current transmitted through overhead wires. A mechanical arm called a pantograph extends from the roof of the streetcar to make contact with the wires.

The streetcar system will employ nine full-time drivers and a staff of about 22 people.

Impact:

Atlanta Mayor Kasim Reed has high hopes that the $98 million streetcar system will have a positive economic impact on downtown Atlanta, stimulating development and promoting business and tourism. He recently suggested that the system might one day be connected to the Atlanta Beltline, a 22-mile ring of disused rail lines being turned into parks, walking trails and green spaces.

The Atlanta Streetcar will be available to the crowds attending the Chick fil-A Peach Bowl at the Georgia Dome and the annual New Year’s Eve peach drop at The Atlanta Underground.