Ideas on Traffic

I commute from Orem to Salt Lake City (Utah) daily. As traffic begins to grow I'm curious to know what would be a better solution to the problem. Currently they are adding an additional lane for a long stretch of I-15. It will be a carpool lane and hopefully very helpful as I ride the Bus. However for long range planning an emergency planning I wonder if the more beneficial alternative would be to create a separate parallel road. If the DOT were to build a parallel road it would seem to easy the flow of traffic on both roads and in case of an emergency there would be an alternative route. There have been a number of times in the past few years when a gas truck has overturned, (or something similar) and both sides of the interstate were at complete standstills with little option for alternative routes. Coworkers were forced to stay at the office for the night as hopes of getting home that night began to fade as traffic piled up. Should a major disaster occur it would be beneficial to have alternative routes. Let me know what you think. Have you read any literate on this topic?