Hannibal Street Department personnel were installing additional bases for safety bollards Thursday.

Traffic on North Main Street, near North Street in Hannibal was reduced to one lane Thursday while a Hannibal Street Department crew installed bases onto which safety bollards can be attached.

It was anticipated the installation of seven bases would be completed Thursday in time for use during this weekend’s Big River Steampunk Festival in downtown Hannibal. The installation proved to be more of a challenge than anticipated. As workers dug into the pavement, they encountered bricks, concrete and even voids beneath the asphalt.

As a security measure, the bollards — which weigh 90 pounds apiece — are installed along North Main Street and its side streets during major downtown events. The bollards are spaced far enough apart that a car or truck cannot pass between them.

Approximately 70 bases were installed this spring.