Charlotte Area Transit (CATS) LYNX Blue Line Extension and Transit Facilities Surveying

The LYNX Blue Line is the first light rail service in the Charlotte metro area. The 18.9-mile long track operates from I-485 at South Blvd to UNC Charlotte’s main campus.

The LYNX Blue Line Extension project spans 9.3-miles from 7th Street Station in Uptown Charlotte through the NoDA (North Davidson) and University areas.

For the LYNX Light Rail I-485 Station survey project, SEPI collected cross-section data along 400 feet of both tracks one and two. Field procedures were conducted to establish control points by GPS. The cross-section of the rails and station were taken by utilizing Robotic Total Station and high definition 3D laser scanning. Data collected allowed for temperature variations, settling, and other aspects that could affect movement in the tracks.

SEPI conducted one night-time visit to verify the difference between temperature effects on overhead power. A spread sheet was developed along with a CADD drawing to indicate the degree of movement of each point located within 25 foot cross-sections for the 400 foot length of the station and extending 75 feet beyond each end of the station.

For the CATS South Corridor Storm Drain Location project, SEPI collected horizontal and vertical data of the storm drain structures within the right-of-way of the nine-mile existing LYNX Blue Line Rail System. Field procedures were conducted to establish control points by GPS at each of the 10 train stations and various points along the nine-mile route where storm structures were located.

SEPI coordinated weekly with CATS to gain access to the rail right-of-way and request the assigned CATS flagman to be on-site during field operations. When storm structures were within the rail ballast, SEPI used a probing rod to determine if the top of the structure was more than two-feet deep, if so the structure was not uncovered.

All data collected was referenced to NC Geodetic Grid System (horizontal NAD 83, vertical NAVD 88). A spread sheet was developed along with a CADD drawing to indicate the difference of the design plans as to as-built information.