NJ Transit and an engineers’ union appear to be heading toward a major rail strike that would start Friday — the first one in decades. Currently, both sides are in Washington, D.C. participating in mediation,

The union that represents the engineers who drive New Jersey Transit’s commuter trains has threatened a walkout as soon as Friday if a contract deal is not reached.

Transit agencies across the region are rolling out emergency plans as a possible NJ Transit rail strike threatens to disrupt service for riders starting Friday.