Saanich police are investigating two incidents of items being thrown down from overpasses onto passing vehicles on Wednesday.

The first incident occurred at 1:20 p.m., on Interurban Road at the McKenzie Road overpass. An falling object shattered the sunroof of a Hyundai Accent travelling southbound. The 21-year-old woman driving sustained minor lacerations to her face.

"We didn't find the object and we didn't find where the object came from," said Sgt. Julie Fast. "It is believed the object came from from the top of the McKenzie overpass and either fell or was thrown down."

Later Wednesday evening, police received two calls about eggs being dropped onto vehicles travelling near Trans-Canada Highway and McKenzie Road from a pedestrian overpass.

Police were on the scene by 10 p.m., but nobody was on the overpass. An empty egg carton was left behind.

"An egg is a very benign object; when it hits a car it's likely not going to do any damage," said Fast. "Where the (danger) comes in is when cars are travelling at highway speeds -- we don't expect things to hit our car from the sky, except rain, hail or snow. If we catch something coming from our periphery ... all we see is an object coming towards us."

That can lead drivers to make evasive moves, such as swerving, braking or accelerating to avoid the object.

"When we start doing all those things, we can find ourselves in a place where a crash is going to happen," Fast said.

If, as a driver, you believe someone is going to throw something at your vehicle, Fast advised you quickly decide how to defensively manoeuvre the situation: be it swerving, braking or accelerating.

If something is dropped from above, pull over where it is safe to do so and call police.

Last November, a rock, 25 cm in diameter, was dropped through the windshield of a bus from the pedestrian overpass at Trans-Canada and McKenzie. Similar incidents were reported around the same time from the same overpass, as well as the pedestrian overpass at McKenzie and Carey roads.

"There are enough calls about this (every year) that it's something we're concerned about, "Fast said, adding that Saanich police deal with around 100 calls a year about objects being dropped onto roads.

"Eggs are more or less youthful antics, but when we start dropping rocks and bricks and objects that are a little more ominous, then the ante has just been raised," she said. "Most of us know that when we take a hard, heavy object and we drop it, there's likely going to be damage."

kslavin@saanichnews.com