Texas transportation officials say they will need about $4 billion more per year to maintain and improve the state's aging highway system and keep its growing population moving. Phil Wilson, executive director of the state Department of Transportation told House lawmakers that Texas is nearing the end of a decade of construction and maintenance fueled by bonds and other revenue sources. Wilson says that without new money, state roads are facing a "perfect storm" of a growing population trying to use aging highways. Gov. Rick Perry has said he wants to spend more than $3 billion from the state's Rainy Day Fund for water and road projects. The Legislature also is considering a state constitutional amendment to dedicate billions in annual car purchase sales taxes to highway construction.