The Treasury Department's suggestion that future traffic be cut off along Pennsylvania Avenue in front of the White House, would be similar to erecting a mini-Berlin Wall across Washington.

Getting between the areas west and east of the White House is tough enough today without disrupting the avenue. North of the Mall, there are only Constitution Avenue, E Street and Pennsylvania Avenue -- all congested during rush hours -- until one gets north of Lafayette Square to the congenitally gridlocked H, I and K streets. With Pennsylvania Avenue closed off, one can foresee utter traffic chaos in the central city, as D.C. City Council Chairman David A. Clarke and Rep. Frank Wolf (R-Va.) have predicted.

This would be the third traffic encroachment by the White House.

First, north-south traffic was eliminated on West Executive Avenue between the White House and the Old Executive Office Building. Security reasons were claimed (and probably were reasonable, since the president's office is in the West Wing); but West Executive Avenue never was a major traffic artery anyway.

Then, a year or so ago, north-south traffic (chiefly by Virginia commuters) was eliminated on heavily traveled East Executive Avenue between the White House and the Treasury, again on asserted security grounds. That street has since been turned into a parking lot for White House employes, making one wonder whether security wasn't a ruse.

If Pennsylvania Avenue is closed, can E Street, behind the White House and separating it from the Ellipse, be far behind, completing the Berlin Wall effect? (At one time, 30-odd years ago, the idea of tunneling E Street beneath the Ellipse was considered, but dismissed as too costly. Is it an idea worth reviving?)

A further note: Closing the affected section of Pennsylvania Avenue to all vehicular traffic would disrupt the bus system and force service-delaying reroutings and terminal changes. Public transit, in one form or another, has passed along that stretch of Pennsylvania Avenue since Gilbert Vanderwerken began running horse-drawn omnibuses in 1830.