On the same road: rival traffic reporting firms merging.(Metro Traffic and Express Traffic)

The Philadelphia region's archrival traffic-reporting services are on the road to a partnership, thanks to a planned merger of their parent companies.

Metro Traffic and Express Traffic, competitors for much of the past decade in Philadelphia, said they plan to combine certain operations but retain separate identities after Express parent Westwood One completes its acquisition of Metro Networks Inc.

"We'd look at the synergies - that would just make sense," said Warren Maurer, regional vice president with the Westwood One subsidiary, who expects the traffic services to maintain something of a "sibling rivalry" despite their common corporate umbrella.

But the deal, announced last week, would no doubt cool the intense competition between the services.

Metro became the …