It's too soon to assess the full impact on business, but the first Saturday of Metro subway operations produced an immediate increase in traffic through retail stores, merchants near Metro stations reported yesterday.

The number of shoppers entering the downtown Woodward & Lothrop store through the Metro entrance was "parallel to a normal day in the Christmas season," said William McDonald, vice president for marketing.

The Crystal Underground shopping complex in Arlington "had more people in the center than we've ever had before," said Larry Demeree, director of retail operations for Crystal City's developer, the Charles E. Smith Co.

But retailers were quick to note that increased traffic does not necessarily mean increased sales, and that it will take several weeks of Saturday subway operations to accurately assess the impact.

"There was decent traffic Saturday. It was a good Saturday, but we did not see any marked increase in (sales) numbers." said Marshall Hillsberg, vice president for sales of the Hecht Company.

"It's typical of any major change like this that things build slowly rather than jumping immediately," added Hillsberg. He said Hecht executives expect Saturday metro service to contribute to better sales.

At Crystal Underground - which also has a direct entry from the Metro station - Saturday subway service should make business on that day as strong as it is during the week, said Demeree. Saturday has been the slowest day for the complex, which draws most of its retail trade from workers in the Crystal City complex above it.

Demeree said the crowds last Saturday "weren't suit tire kickers" but merchants reported business was not up as much as the traffic.

Woodies, which has been touting the benefits of its subway entrance since the trains began running, said store traffic is "up somewhat" at night now that subway hours have been extended.