Police yesterday began conducting security checks near the Federal Reserve building, and authorities announced that they would temporarily shut down a sidewalk next to the Treasury Department in response to terror threats against financial institutions in the District.

Officials stopped short of halting truck traffic next to the Treasury building on 15th Street NW as they continued to wrestle with how to balance security measures against traffic, commerce and tourism.

Federal and city officials said yesterday that they still might ban truck traffic on the busy thoroughfare if the security situation changes.

"We continue to monitor and evaluate changing events in order to implement the most appropriate and effective security measures," said Lorie Lewis, a spokeswoman with the U.S. Secret Service.

In coming days, Lewis said, the Secret Service will use metal barriers to close the sidewalk on the west side of 15th Street from about Pennsylvania Avenue to Alexander Hamilton Place.

The enhanced security measures follow Sunday's announcement by Homeland Security Secretary Tom Ridge citing the terrorism threat to financial institutions in Washington, New York City and Newark, specifically naming the International Monetary Fund and the World Bank in the District.

At the Federal Reserve yesterday, police began conducting checkpoints during the morning rush hour at four intersections surrounding the central bank: at Constitution Avenue at 20th and 21st streets NW, and Virginia Avenue at C and 21st streets.

Federal Reserve and D.C. police officers allowed cars to pass with only a glance through the windshields. But they pulled over several trucks and vans to inspect manifests and peek at their cargo. Officers said the day had been relatively routine.

Police are conducting similar checkpoints near the IMF and World Bank and have restricted parking near the institutions.

D.C. Police Chief Charles H. Ramsey, who raised his department's alert status after Ridge's announcement, said yesterday that he did not yet know how much the added security would cost his agency. He has been promised that the city will be reimbursed by the federal government for the cost of protecting the IMF, World Bank and other buildings, he said.

Early in the week, U.S. Capitol Police shut down part of First Street NE in response to the threat of truck bombs. The Capitol Police also set up more than a dozen checkpoints aimed at making it difficult for potential bombers to get near congressional buildings.

D.C. leaders have assailed what they call an opportunistic encroachment on city streets by security officials taking advantage of terrorism threats.

In an effort to prevent federal and local agencies from haphazardly instituting security measures, the National Capital Planning Commission yesterday approved its first development blueprint for the region in 20 years, aiming to coordinate long-term planning between federal and local jurisdictions.

"We have to be very careful about ratcheting up the level of security beyond where it needs to be, for the simple reason that we do have to keep this an open city, a free city, a place where we all want to be proud of what we do and how we live," said John V. Cogbill III, chairman of the commission.

The commission is the central planning agency for the federal government and provides guidance for federal land and buildings throughout the region.

The comprehensive plan would not prevent officials from closing streets or erecting temporary barricades but encourages federal and local officials to work together to determine how to react to threats.

"It's something we continue to address, but I think in light of where we are today in the security environment, it's always important to remember that we do have guidelines, that we do have ways to deal with this," Cogbill said.

Staff writer Monte Reel contributed to this report.

Officers Kevin Hill, left, with the Federal Reserve, and Garret Robinson, with the State Department, work a checkpoint near the Federal Reserve.A police officer and his dog patrol along the Federal Reserve on Constitution Avenue NW. Four new checkpoints were set up around the Federal Reserve during the morning commute yesterday.