"It's the point where the contractor says to the owner, UTA, that they pretty much have all their work done and can turn it over to begin testing," Carpenter said. "A rail line is different than a highway. You can't start driving on it the day you hit substantial completion. You have to do many different phases of testing to make sure it is safe and ready for the public."
Before any testing begins, officials from the Federal Transit Administration are scheduled to visit in January and review the work and its documentation to ensure it meets standards.
"If everything goes well with the FTA in January, we should be able to begin 'system integration testing' in mid-February," Carpenter said.
That is about six weeks of "moving trains very slowly down the alignment and making sure that all the systems are working and communicating," Carpenter said, such as "the gate arms come down at crossings." That is followed by a two-week review to certify testing was proper.
If all goes well, "around mid-April we'll be ready to begin training operators on the line" over a 60-day period, where more trains will use the line at full speed and simulate real schedules. That could go into July, when the FTA is expected to do a final review and certification.
Carpenter said the long process of testing and certification is the same "whether it is a 3.8-mile line like Draper, a 6-mile line like the airport or a 45-mile line like FrontRunner," which just opened an extension from Salt Lake City to Provo.
Also affecting the timing of opening the new line is that UTA tries to open new lines on one of the three days a year when it changes schedules, which usually are in April, August and December.
Carpenter said the new Draper line will get a little additional federal attention because 60 percent of its funding is federal. Most other recent UTA rail additions the new FrontRunner line, the airport line and a line to West Valley City were built with all-local funding. However, 80 percent of the cost of the mid-Jordan TRAX extension to Daybreak that opened last year came from federal funding.
Taxpayers in Salt Lake and Utah counties in 2006 approved raising sales taxes by a quarter of a percent, which helped build and speed all those projects which were originally proposed to be built by 2015.
"The new Draper line is the last of the 2015 projects," Carpenter said. "The whole program will be wrapped up about two years ahead of schedule."
The new Draper line will add three stations to the south end of the blue line at 11400 South, 11800 South and at Pioneer Road (12400 South) in Draper. UTA has plans to eventually extend the line even farther to 14600 South, and perhaps later even into Utah County.