WASHINGTON—A new report published Monday by the National Transportation Safety Board advises motorists that sending text messages while driving “is totally fine” and “not that big a deal” as long as you make sure to glance up from your phone every now and then. “If you’re driving and have a really important text to send, that’s okay; just try to keep one eye on the road as best you can,” NTSB chairman Deborah Hersman said of the report, which advocates a new “50-50 rule” for texting drivers, suggesting they keep half their attention on the road and half on their handheld device. “After all, you can always steer with your knees or—if you really want to be extra careful—text with one hand and hold the wheel with the other. Better yet, just ask a passenger to give you a heads-up whenever there’s a red light or another car up ahead.” Hersman added that the report’s findings apply not only to texting, but also to checking email, playing games, or watching movies while driving.