When the A-line rapid-bus service debuted two summers ago, transit planners called it a “historic” addition to the Twin Cities’ public transportation network. Since then, the A-line has proved to be a star performer for Metro Transit, with ridership along the route increasing by more than a third in its first year alone.

In the coming years, 10 more rapid-bus lines will snake throughout the metro’s busiest transit corridors — and last week, the network’s build-out reached two milestones. Advocates say rapid-bus service offers passengers a light-rail-like experience but is far cheaper to build and maintain.

On Wednesday, the Metropolitan Council approved a $13 million contract with Thomas and Sons Construction of Rogers to build the C-line, the Twin Cities’ third rapid-bus line, which will run from downtown Minneapolis to the Brooklyn Center Transit Station, largely along Penn Avenue. The $37 million C-line is expected to begin passenger service next year.

And Metro Transit is seeking feedback on station plans for the D-line along the Route 5 corridor, which has the highest bus ridership in the Twin Cities, running from Brooklyn Park to the Mall of America.

Rapid-bus service is generally faster than traditional buses. A 2012 study found that regular buses in the Twin Cities were moving just 42 percent of the time they’re in service; otherwise, they’re boarding customers, sitting at red lights or stuck in traffic.

Time is saved because there are fewer rapid-bus stations (and therefore, fewer stops), and passengers pay their fares before boarding, so the bus doesn’t need to hover while riders fish out their fares or Go-To cards. Passengers can board at the front of the bus as well as the back. And curbs are extended, so buses don’t have to pull in and out of traffic.

In addition, rapid buses have traffic signal prioritization at certain intersections — meaning they can “ask” signals for early or extended green lights so they can keep moving.

“The A-line has so far been extremely effective in achieving a 25 percent reduction in running times, which is quite significant on an urban corridor like Snelling Avenue,” said Andrew Guthrie, a doctorate candidate at the Humphrey School of Public Affairs at the University of Minnesota.

Metro Transit says the A-line corridor has seen 5 percent month-over-month increases in ridership during its second year. The A-line is well situated, because it serves the Blue Line 46th Street LRT station on one end and Rosedale mall on the other. In between, there’s the Snelling Avenue Green Line LRT stop, the State Fairgrounds and several colleges, including Macalester and Hamline.

“Some people do have to walk more to get to the bus stop, so it can be inconvenient, especially if people are senior citizens, or people with strollers,” said Jessica Treat, executive director of Transit for Livable Communities & St. Paul Smart Trips.

But, Treat notes, the rapid-bus stops are heated and well lit, and they have pylons with real-time arrival information.

Because rapid buses operate in traffic, they can get ensnared in gridlock and are susceptible to potholed roads. Road construction last year meant “a lot of orange cones along Snelling Avenue,” said Katie Roth, manager of arterial bus rapid transit for Metro Transit. Now that the construction is done, “we’re back up to higher than 90 percent on time in the corridor,” she said.

The C-line fleet will feature eight emissions-free electric buses — a first for the Twin Cities. The 60-foot accordion buses will be fully propelled by rechargeable batteries.

“The biggest difference for customers will be on the street side,” Roth explained. “Riders won’t experience diesel exhaust fumes and the noise will be a little different. Are the buses quiet in a way that’s a little too quiet? We need to make sure that’s not a safety issue.”

The continued rollout of rapid-bus service in the Twin Cities comes as overall bus ridership here and nationwide is declining. Transit wonks have attributed this trend to a number of factors, including a perceived lack of reliability, an improving economy that encourages car use and the popularity of ride-sharing services such as Uber and Lyft.

Guthrie, of the Humphrey School, said local bus service has changed little since the streetcar era in the early 1900s.

In 2016, Metro Transit logged 58 million rides on buses, a 6.5 percent decline over the previous year. (A fare increase, which went into effect Oct. 1, may have dampened ridership, at least initially.)

Roth says a wider web of rapid-bus routes better serves existing riders but would likely attract new ones as well. “What we’ve seen with the A-line is that it has reinvigorated ridership,” she said. “People are really responding to this investment.”

Guthrie said both the C-line and D-line have “positive social equity implications” because they will serve north Minneapolis. “Rapid bus offers much higher quality of bus service in an area with great demand and great need for it, but without having to tear up streets and condemn property, which would have been necessary if the [Bottineau] Blue Line” extension would have followed Penn Avenue, he said.

The proliferation of rapid-bus lines is also occurring as many Republican lawmakers at the State Capitol have been loath to fund additional light-rail lines, such as the Southwest and Bottineau projects, which cost $1.9 billion and $1.5 billion, respectively.

Rep. Paul Torkelson, R-Hanska, chairman of the House Transportation and Finance Committee, said bus lines “in general make a lot more sense than light rail.”

The rapid-bus projects are funded with a mix of federal, state and local funds, and the C-line is fully funded. With 23 stations, Metro Transit expects more than 9,000 weekday riders on the C-line by 2030, up from 7,600 daily passengers on the Route 19 bus now.

The $75 million D-line will augment the busy Route 5 bus corridor, which serves an average of 16,000 riders on weekdays, with 23,000 passengers expected by 2030.

Gov. Mark Dayton’s bonding proposal for this legislative session includes $50 million for regional bus-rapid transit investment, including $35 million for the D-line.