Are personal injury settlements taxed?

A friend was involved in a major traffic accident. My friend was driving a semi (18 wheeler on the interstate). The other person (driving a car) apparently suffered a fatal heart attack, and crossed the median, hitting my friend head on, at full speed. Needless to say, the other guy didn't survive- he'd only been out of the hospital 4 days, and out driving. The semi was totaled. My friend had to have neck surgery, and it's likely he will never be hired to drive again, with the neck & shoulder issues. It's all he's EVER DONE since 18 yrs old. He's now 57. Possibly be disabled. He's in recovery. His wife is beside herself. They have a mortgage to pay, a teenage son to provide for (who will go off to college in 3yrs), and it's looking as though she will be the sole breadwinner. They're going to sue the guy's insurance company, as my friend still has @10 yrs left til full retirement age. Disability or a replacement income is very uncertain at this point. So, if anyone knows if insurance settlements are taxed, it would be helpful. It's going to determine the bottom line settlement they seek. It's been a horrible mess. They deserve to be compensated fairly, just asking if they need to take taxation into consideration?