The laws in most states require that flares be carried when towing. My old incindiary flares were pretty well squashed after riding under the back seat of the truck for about 10 years.
I recently found a nice set of 2 electronic flares called "Turboflare 360" at Sam's. They take 4 AA batteries each and put out a very bright rotating light pattern.
John W. Irwin
2005 Classic 28 "Sabre-Dog III"
2013 Silverado 2500HD Duramax/Allison LTZ
WBCCI #9632, TAC TX-10