Construction on the new Tappan Zee Bridge is expected to cause a change in some traffic patterns and possible delays over the several days.

On the Rockland side, crews will begin installing steel girders near the shoreline next week. This begins the process of securing the new bridge's Rockland connection to the already-installed support structures in the Hudson River.

Unfortunately the work will require reducing River Road to one lane during weekdays between 6 a.m. and 5 p.m.

State officials say flag persons will keep traffic moving by alternating the directional flow between north and south. In addition, traffic on River Road will be stopped at least once daily next week between 9 a.m. and 3 p.m. for up to 20 minutes. The purpose is to enable the safe movement of girders and other materials during the construction of the new $3.9 billion bridge.

Two toll lanes at the Tarrytown Plaza were shut down today for five hours but had little impact on traffic crossing the span.