Maryland Gov. Larry Hogan (Jonathan Newton/The Washington Post)

The NAACP on Monday filed a federal civil rights complaint against Maryland, alleging that the state discriminated against African American residents in Baltimore when Gov. Larry Hogan killed the Red Line rail project and diverted state money to road and bridge projects elsewhere.

“This is a critical civil rights issue,” said Sherrilyn Ifill, president of the NAACP Legal Defense and Educational Fund. “Everyone who knows this city knows that the lack of rapid transit restricts access to jobs and housing for low- and middle-income African American residents living along the city’s east-west corridor.”

The defense fund and the American Civil Liberties Union of Maryland are asking the U.S. Transportation Department to investigate whether Maryland violated Title VI of the Civil Rights Act of 1964 when Maryland scuttled the 14-mile, $2.9 billion rail project.

The complaint was filed on behalf of the Baltimore City chapter of the NAACP, Baltimore Regional Initiative Developing Genuine Equality (BRIDGE) and African American residents.

A spokesman for Hogan said the complaint has “zero credibility or legal standing,” noting that the first-term Republican governor recently announced a $135 million plan to revamp Baltimore’s bus system and “has been fighting for increased highway user revenues since the moment he stepped into office.”

“Governor Hogan is fully committed to improving transportation in Baltimore,” spokesman Doug Mayer said in a statement. “The Red Line didn’t move forward because it was poorly designed and simply unaffordable, with at least a billion-dollar tunnel running through the heart of the city.”

A spokesman from the Transportation Department declined to comment on the complaint but said that such filings are not uncommon.

The civil rights complaint could add to simmering tensions between Hogan and city leaders, who have criticized the governor over school funding priorities and his unilateral decisions to close the city’s detention center and cancel the rail line. The filing could also pose a political challenge for Hogan as he tries to balance the needs of heavily Democratic Baltimore — still reeling from last spring’s riots following the death of Freddie Gray while in police custody — with the needs of the rural and suburban areas where most of his supporters live.

Matthew Crenson, a political science professor at Johns Hopkins University, said Hogan’s relationship with Baltimore is not likely to cause trouble for the Republican, given the city’s lessening political clout. “It’s the Washington suburbs that he has to hold on to,” Crenson said.

At the same time, Hogan has repeatedly said he wants to make a difference in Baltimore. On Monday, his administration announced a state effort to provide one free book each month to infants and preschoolers in the city.

Hogan rejected the Red Line in June, asserting that the project would not be a financially effective method of attracting jobs. At the same time, he pumped more money into highway projects in suburban and rural areas across the state and supported a slimmed-down version of the Purple Line rail project that will connect Bethesda and New Carrollton in the Washington suburbs.

“Shifting resources from public transit in Baltimore to highways and bridges outside of the city has a discriminatory impact on African American residents,” Ifill said Monday. “Baltimore residents rely on public transportation to travel to work and school. The governor has not offered an appropriate alternative to ease public transit woes in Baltimore.”

The complaint asks the federal government to stop transportation funds to Maryland unless it agrees to resume construction of the Red Line or adopts a “less discriminatory” alternative.

The Rev. Bob Walker of BRIDGE called transportation the “linchpin” for education, housing and jobs. The absence of a rail link through the city’s east-west corridor has left areas such as Sandtown, where Gray lived, impoverished, he said.

According to the lawsuit, a transportation economist found that whites will disproportionately benefit from Hogan’s decision to cancel the Red Line and use some of the money for other projects and that African Americans will be negatively affected.

“The decision to cancel the Red Line and divert the resources elsewhere was only the latest in the state’s long historical pattern of deprioritizing the needs of Baltimore’s primarily African-American population, many of whom are dependent on public transportation,” the complaint reads. It calls the decision “a naked transfer of resources from the project corridor’s primarily African-American population to other rural and suburban parts of the state, several of which have predominantly Caucasian populations.”

The Red Line would have given workers better access to employment centers such as Johns Hopkins University, Ifill said. Without the rail link, she said, many residents have to leave home while it is still dark to catch multiple buses to jobs, leaving their children to get to school by themselves.

Tessa Hill-Aston, president of the Baltimore City NAACP, said some residents struggle to find bus transportation that matches their work schedules.

Hogan’s proposal in October to improve bus service in the city drew a negative response from Mayor Stephanie Rawlings-Blake (D) and Baltimore County Executive Kevin Kamenetz (D), and a spokesman for the mayor reiterated that disappointment on Monday.

“We don’t think the plan measures up,” said spokesman Howard Libit. He said the mayor could not comment on the NAACP complaint, because she had not reviewed it.

Ashley Halsey III contributed to this report.