In the Design Manual's Chapter 325, “Design Matrices Procedures,” there are five matrices that address the majority of preservation and improvement projects, focusing on those design elements of greatest concern in project development.For more information on the use of these Design Matrices, see Chapter 325 of the Design Manual.
Design Matrix 1 - Interstate Routes (Main Line)
Design Matrix 2 - Interstate Interchange Areas
Design Matrix 3 - NHS Routes (Main Line)
Design Matrix 4 - Non-Interstate Interchange Areas
Design Matrix 5 - Non-NHS Interchange Areas
There are three minor operational enhancement project matrices that address guidelines and documentation requirements without unduly impeding the processes. Typically, these are Q projects administered by the Traffic Office. For information on the use of these matrices, see Chapter 340 of the Design Manual.
Minor Operational Enhancement Matrix 1 - Interstate & NHS Freeway Routes
Minor Operational Enhancement Matrix 2 - NHS Non-freeway Routes
Minor Operational Enhancement Matrix 3 - Non-NHS Routes