The first major overhaul of Baltimore’s bus system will take effect early this morning, replacing a network fashioned generations ago with a color-coded transit operation meant to improve reliability.

“The system we have today, quite honestly, is not reliable,” said Kevin Quinn, acting administrator for the Maryland Transit Administration.

More than 300 volunteers and 5,000 new bus stop signs will be deployed starting at 3 a.m.today. Numbered routes have been replaced with 12 color-coded, high-frequency lines radiating from downtown, linked together with less frequent local connectors.

Bus service, light rail and Metro will be free until the end of June as riders adjust to the changes.

The $135 million revamp of the city’s bus system, called BaltimoreLink, was more than 18 months in the making.

The new routes, Quinn said, were designed based on existing ridership trends and the desire to get more riders to work via public transit.

Some longtime riders have objected to the disruption of their routines and promised to protest today along eliminated routes.

Quinn, who just this month took over the agency after leading the BaltimoreLink project, said the state will have “ambassadors” fanned out at 150 heavily trafficked bus stops, riding buses, and at a half-dozen busy transfer spots until Wednesday.

Drivers will be surveyed after every route to check on how the new bus system is working, but the agency will not release an analysis of the new program for several weeks, Quinn said.

ecox@baltsun.com

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