The agency behind the MoPac express lane project is now seeking to finance a new toll project on US 183 in Northwest Austin. The board of directors for the Central Texas Regional Mobility Authority approved Wednesday to pursue funding options and assess phasing construction of the US 183 project. Options for financing would include bonds from the credit markets, federal grants and public-private partnerships. “The great news is we’re potentially entering the next phase of this project, moving toward implementation,” said Justin Word, the Mobility Authority’s director of engineering. Mobility Authority Executive Director Mike Heiligenstein said if the project becomes funded, construction could begin in early 2018. 1. The project involves more than toll lanes. Two express, or tolled, lanes would be added to US 183 from MoPac to RM 620 as well as a fourth nontolled general-purpose lane. Other project elements include direct connectors, or flyovers, from US 183 to RM 620 and to MoPac as well as 8.5 miles of new sidewalk and 1 mile of new shared-use path. On Wednesday, Heiligenstein said the project cost is upwards of $500 million, but previous estimates from the agency have been as high as $650 million.  An initial cost based on preliminary estimates of $225.7 million was adopted in the Capital Area Metropolitan Planning Organization. In 2015, the agency reported the cost would be between $500 million and $600 million. Heiligenstein previously told Community Impact Newspaper the cost increases are a result of the project scope expanding. 2. Because of the cost, the project likely will be built in phases. Up first would likely be restoring a fourth nontolled lane throughout US 183 to correct the lane imbalance that shifts between three and four lanes as well as to address traffic congestion. The section is estimated to cost about $120 million, Word said. The second phase would be adding the two tolled lanes in each direction, direct connectors to MoPac and other nontolled elements, such as sidewalks. The final phase would be to add the direct connections to RM 620. Those would land near Deerbrook Trail in the Anderson Mill neighborhood. “Likely when RM 620 is improved in some way by TxDOT or others, at that time we’ll build those direct connectors,” Word said. 3. There’s some concern over the agency being able to handle the project financially. Board member David Armbrust asked Heiligenstein if the agency had the financial capacity to take on another significant project. “Is there a point where the financial markets will look at us and say, ‘You just didn’t do much here. You’re extended too far,’” he said. “Is this impacting anything else we’re doing?” Besides the MoPac project between Parmer Lane and Cesar Chavez Street, the agency is also planning a similar express lane project on MoPac, south of Lady Bird Lane, and building the 183 South project, which broke ground last April. The $743 million project is expected to quadruple the roadway's capacity by building three tolled lanes in each direction between Hwy. 290 and Hwy. 71. The project also includes three nontolled lanes in each direction with bike lanes and a shared-use path. Heiligenstein said phasing the project will help with finding funding, and the future traffic and revenue study would also help. “Every project we have becomes added into the system itself,” he said. “We do the due diligence ahead of time to make sure the credit markets are comfortable with coverage.” Word said staffers would come back to the board in a few months with some financing options.