A snippet I found in the Peer Panel Review report:

"The Gold Line Eastside Extension is approximately 5.8 miles in length with a mixed operating environment. The line is predominately street running, with a top operating speed of 35 mph. At no time is the operating speed greater than the posted speed limit for vehicular traffic. The grade crossings are wide offering for the most part excellent sightlines. As mentioned earlier, this type of alignment, combined with the operating characteristics, does not justify or require the installation of crossing gates. Other segments of line include a 1.7-mile tunnel with a maximum operating speed of 55 mph, and a short aerial structure with an operating speed of 10 mph. The low operating speed on the aerial structure is due to the curvature of the bridge and steep grade."