A police car in Alexandria, Va., that has been equipped with a license-plate scanner. (Pablo Martinez Monsivais/AP)

The Department of Homeland Security is seeking bids from companies able to provide law enforcement officials with access to a national license-plate tracking system — a year after canceling a similar solicitation over privacy issues.

The reversal comes after officials said they had determined they could address concerns raised by civil liberties advocates and lawmakers about the prospect of the department’s gaining widespread access, without warrants, to a system that holds billions of records that reveal drivers’ whereabouts.

In a privacy impact assessment issued Thursday, the DHS says that it is not seeking to build a national database or contribute data to an existing system.

Instead, it is seeking bids from companies that already gather the data to say how much they would charge to grant access to law enforcement officers at Immigration and Customs Enforcement, a DHS agency. Officials said they also want to impose limits on ICE personnel’s access to and use of the data.

“These restrictions will provide essential privacy and civil liberty protections, while enhancing our agents’ and officers’ ability to locate and apprehend suspects who could pose a threat to national security and public safety,” DHS spokeswoman Marsha Catron said in a statement. The solicitation was posted publicly Thursday.

Privacy advocates who reviewed a copy of the privacy impact assessment said it fell short.

“If this goes forward, DHS will have warrantless access to location information going back at least five years about virtually every adult driver in the U.S., and sometimes to their image as well,” said Gregory T. Nojeim, senior counsel for the Center for Democracy & Technology.

Commercial license-plate tracking systems already are used by the FBI and the Drug Enforcement Administration, as well as some local and state law enforcement agencies. Law enforcement groups say the fears of misuse are overblown. But news of the DHS solicitation triggered a public firestorm last year, leading Homeland Security Secretary Jeh Johnson to cancel it and order a review of the privacy concerns raised by advocates and lawmakers.

Over the following months, ICE and DHS privacy officials developed policies aimed at increasing “the public’s trust in our ability to use the data responsibly,” according to a senior DHS privacy officer. The DHS is the first federal agency, officials said, to issue a privacy assessment on such a solicitation.

Commercial license-plate-tracking systems can include a variety of data. Images of plate numbers are generally captured by high-speed cameras that are mounted on vehicles or in fixed locations. Some systems also capture images of the drivers and passengers.

The largest commercial database is owned by Vigilant Solutions, which as of last fall had more than 2.5 billion records. Its database grows by 2.7 million records a day.

DHS officials say Vigilant’s database, to which some field offices have had access on a subscription basis, has proved valuable in solving years-old cases. Privacy advocates, however, are concerned about the potential for abuse and note that commercial data banks generally do not have limits on how long they retain data.

ICE said it will restrict agents’ access to the data to the number of years corresponding to the relevant statute of limitations for any crime being investigated. For civil immigration cases, where there is no statute of limitations, the agency is adopting a five-year limit, officials said.

ICE officers and agents also will be required to enter the type of crime associated with each query to gain access to the database, and there will be random audits to ensure that no one is using the database to look up information on personal associates. Officers and agents may search only for particular plate numbers.

ICE queries will not be shared with other agencies, unless they are working on a joint investigation, a senior DHS official said. ICE personnel also will be able to put plate numbers of interest on an “alert list,” enabling those personnel to be notified almost instantly when a plate is spotted.

Ginger McCall, director of the Electronic Privacy Information Center’s Open Government Project, said the new safeguards are not “meaningful.” She called the data retention requirements “exceedingly vague” and said tracking a person through alert lists without a warrant is troubling.

The senior DHS privacy officer said case law does not require the government to seek a warrant for such data.

“This is a step in the right direction, but it’s not nearly strong enough, given the particular acute privacy and civil liberties issues implicated by locational data,” McCall said.