Officials with the city of New Braunfels are cautioning residents of an upcoming construction project on the San Antonio Street bridge. The estimated 18-month project will begin Aug. 1 and include infrastructure improvements that will create wider lanes and sidewalks and modernize the bridge to support heavier traffic. The project will undergo staging process during the month of August, while actual construction will not begin until after Labor Day, city officials said. According to city officials, progression of the project will be slow during the first phase in an effort to preserve the architectural and historical integrity of the bridge, along with the nearby Comal River environment. Built in 1923, the bridge fails to meet Texas Department of Transportation structural and functional standards due to a lack of a shoulder and an inability to support the weight of larger vehicles, which has impacted emergency response times, officials said. A piece of TxDOT infrastructure, TxDOT will oversee the project and a complete closure of the bridge, which is expected to occur during the second week of September. Cost of the San Antonio Street bridge project is estimated at $4.5 million with 80% of funding federal, 10% state and 10% from local sources.