Two of the four lines were shut down for regular maintenance.

Regular maintenance is the most important 'improvement' you can make to your home.

Their emergency systems might have run a month, perhaps even two, but in the end the heat and lack of regular maintenance had killed them.

Perform regular maintenance and make sure lights are turned off when not in use.

For several more years the path remained open despite lack of regular maintenance.

It was clear to him by now that no one did regular maintenance in these tunnels.

The first step is to put in place a cleaning schedule as part of your regular maintenance.

But officials worry that without regular maintenance, the capital budget will be less effective.

Pine can last longer than a few years but it requires regular maintenance.

Even after construction began, regular maintenance was still carried out on the bridge.