Rail safety education nonprofit Operation Lifesaver is urging professional photographers to refrain from taking photos of high school seniors, wedding parties, and other subjects on train tracks or trestles.

Last year, more than 800 people were injured or killed while trespassing on railroad property in the U.S., according to preliminary Federal Railroad Administration statistics.

"We know that photographers seek creative portrait settings; however, using train tracks as a backdrop for photos is not only dangerous, it is illegal trespassing," said Operation Lifesaver Inc. President/CEO Joyce Rose, who also noted that about every three hours in the U.S., a person or vehicle is hit by a train.

A teacher who taught art and photography was struck and killed by a train while taking photos on the tracks late in 2012. In response to tragic and preventable incidents like this, Operation Lifesaver has worked with Professional Photographers of America on rail safety education outreach to the professional photographer community.

The group has six "must-know" tips for professional photographers considering a photo shoot near the tracks:

1. Trains can't stop quickly to avoid people or vehicles on the tracks.

2. An optical illusion makes it hard to determine a train's distance from you — and its speed.

3. The average train overhangs the track by at least three feet.

4. Railroad tracks, trestles, yards and rights-of-way are private property.

5. No tracks should be assumed to be abandoned or inactive.

6. People in your community mimic your behavior.