Why do highway signs on the way to Philly only point people to NYC?

Why does Philly rarely get any love on Maryland northbound I-95 signs?

A reader asked that question of Curious Philly — The Inquirer’s platform that lets people send in questions for our reporters to answer.

“Why do all northbound signs on I-95 in Maryland say New York and not Philadelphia or Wilmington? Very irking to me and several million Philadelphia-area residents,” wrote James Udell.

We set out to find the answer. Whether it’ll make you or Udell feel any less irked, well, that’s debatable.

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Cities that appear on signs on interstate highways are based on recommendations by the American Association of State Highway and Transportation Officials (AASHTO), says Bob Cullen, the group’s information resource manager.

AASHTO is a nonprofit, nonpartisan association representing highway and transportation departments for all 50 states, the District of Columbia, and Puerto Rico. It serves as a liaison between state departments of transportation and the federal government.

AASHTO maintains a published list of “control cities,” which it updates periodically. Control cities are locations determined by each state to be major destinations on or near the Interstate Highway System. If you look at the list, both Philadelphia and Wilmington, along with other local destinations, including Chester and Trenton, are marked “95 NB.” In other words, Philadelphia is a candidate for I-95 northbound signage.

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How did New York become the chosen golden child for I-95 NB signs all across Maryland? The idea is that it’s the most recognizable of all the options.

“Using ‘NEW YORK’ as the guide sign destination clearly captures all northbound motorists regardless of their ultimate destination without presenting information which could confuse motorists destined for an interim destination,” says John Sales, Maryland Transportation Authority public affairs manager. “It also maintains consistency with signing along all approach roadways and in adjacent jurisdictions.”

Federal regulations limit the number of destinations that can be shown on guide signs to two per sign. So, if a sign is pointing people in two directions, each can only show one destination.

“Adding additional destinations causes confusion for motorists at a time when they are processing significant amounts of information as part of driving,” Sales says.

» READ MORE: The most curious things we learned about Philly in the past year

Once a primary control city is selected, it’s repeated to create “a clear and consistent message,” Sales says.

But have no fear, if you’re headed from Baltimore to Philadelphia, you’ll get at least a little City of Brotherly Love guidance. Once you approach Delaware, signs appear instructing you to take I-95 North to reach “PHILADELPHIA.” It’s just enough to point you in the right direction.

Have a question related to the region? Send them to us through Curious Philly, inquirer.com/askus.