By Jennifer McRae

DENVER (CBS4)The N Line will open later this month, on Sept. 21. This comes after years of construction, testing and delays on the service between Denver and Thornton.

n line delayed thornton adams county northglenn

The N Line has been delayed until Summer 2020. (credit: CBS)

Ahead of opening day, RTD will increase testing hours to 20 hours a day on the N Line. There will be crossing attendants for added precaution and train horns will be heard over the next few weeks.

n line delayed thornton adams county northglenn

The N Line has been delayed until possibly the summer of 2020. (credit: CBS)

The first 13 miles and seven stations will go through Denver, Commerce City, Thornton and Northglenn before expanding to 18.5 miles and nine stations up to Adams County.

Jennifer McRae