LOS ANGELES (KABC) -- Construction of the new Sixth Street Viaduct, connecting downtown Los Angeles and Boyle Heights, is expected to cost $36 million more and take eight months longer to complete than originally planned.The new completion date is late 2020, with a new cost estimate of $482 million. The original cost estimate for the bridge was $449 million with a completion date in 2018 or 2019.The estimates are based on a refined schedule analysis by the Department of Public Works.The old bridge, which stood for 84 years, is being replaced due to deterioration.