Michigan Intersections
Macomb County (Part of the Detroit Tri-Counties Region)
Controllers
The Solid-State Era
Macomb County initially wanted a solid state controller that mimicked the mechanical controllers due to the unusual timing/cycling patterns of Michigan intersections. [Please elaborate on what makes a Michigan intersection unique.] NEMA phase-oriented machines at the time did not provide as many options and flexibility as they do nowadays.
According to Scott Holzhei of MDOT (user "Kentron" on STF): Eagle Signal was the only manufacturer willing to develop an interval based machine.
First model developed: EF140, interval based machine that was non-NEMA oriented. Individual timed intervals were mapped to specific outputs. Housed in an Eagle Size 4 (G) NEMA cabinet and worked with EDI conflict monitors and TSC load switches. The controller front panel connectors were not NEMA spec’ed
The menu driven model, EPIC140, used the same connectors and cabinet interface, but was menu driven and had more flexible programming. Options included four separate signal plans, time base clock, and pre-emption.
Both the EF and EPIC140 units were sold nationwide but only seen significant usage in Michigan.
EPIC140 controllers with EDI conflict monitors, housed in Eagle Size 4 pole-mounted cabinets became the standard controller used. It allowed for flexible timing and sequences including the flashing red left and single section right turn arrows, pre-timed time-of-day changes.
EPIC140s were also installed in Eagle Size M pole and base mount, M36 and P base mount cabinets and along most major corridors until recently.
