A major British highway linking London with key cross-Channel routes remains closed for a second day as safety officials remove rubble from a collapsed bridge and make sure the rest of it won't fall down as well.

The M20 highway running southeast of London has been closed since midday Saturday, when a westbound truck struck and partly destroyed a pedestrian bridge. A motorcyclist fell off his bike and was hospitalized with broken ribs, while the trucker was treated for shock.

Highways England had hoped to reopen the M20 by midday Sunday. But spokesman Stuart Thompson says the safety checks are proving "very complex," particularly on the part of the bridge that still looms over the highway's eastbound lanes.

Safety officials are installing motion detectors to confirm the bridge remains stable.