Why are there flashing traffic lights on Barker Cypress in the morning and late afternoon?

Can someone please tell me the purpose of a random flashing traffic light? Is it broken? Does it save money in some way? Is it meant to keep drivers from speeding? What it actually does is cause traffic back ups in the morning and late afternoon. It turns my 8 mile commute to and from work into a 40 minute stressful ordeal. Need answers please...about to go postal!