This section defines the diagnostic team as it relates specifically to grade crossings with existing interconnection or potential for interconnection to nearby traffic signals (collectively interconnected crossings) by referring to existing TxDOT processes found in other manuals. This section further defines points of emphasis for interconnected crossings.

23 CFR Section 646, Part 6546.204 defines the diagnostic team as “a group of knowledgeable representatives of the parties of interest in a railroad-highway crossing or a group of grade crossings.” According to the , the diagnostic team consists of the following:

District Railroad Coordinator
Rail Division Representatives
Railroad company Project Manager
Railroad company Signal Maintainer (as needed)
Local government representative (as needed)
FHWA or FRA representative (as needed)

Note, quiet zone diagnostic reviews require participation from FRA whether the crossing is/will be interconnected or not.

Although typical TxDOT processes should be followed, interconnected crossings have unique complexities that should be carefully considered by the diagnostic team. Additional individuals that should be included in the diagnostic team for such crossings include the following:

District Traffic Signal Specialist
District Traffic Operations Engineer

TxDOT Rail-Highway Operations Manual, Chapter 4, Section 3 defines the areas of focus of the diagnostic team. For interconnected crossings the following elements are critical:

Potential for on-track queuing
Existing train operations and future plans
Safety enhancements such as signing and striping, lighting, railroad flashing lights/gates/cantilevers, and traffic signal preemption
Additional turn lanes for improved normal and preemption operations
Consideration for protected left-turns, especially for left-turns crossing and approaching the tracks
Potential conflicts and clearances for placement of both traffic signal and railroad equipment
Pedestrian considerations such as crosswalk placement and pedestrian demand

Table 2-1 below lists documents that provide additional information for the diagnostic team process.

The Diagnostic Team should use this manual as a guide to inform decisions and to define standard application once a specific treatment is identified.