Why did the McDonald’s customer cross the road? To get some fried chicken.

Shares of McDonalds dropped more than 5 percent on Tuesday after the world’s largest restaurant company said US sales sagged last quarter while consumers were going bonkers for fast-food chicken products.

Sales of grab-and-go chicken meals were already doing well when Popeyes unveiled its new chicken sandwich in August — kicking off a social media-inspired chicken sandwich war that saw the Louisiana-style fried chicken maker run out of inventory after just two weeks.

KFC, Popeye’s and Chick-fil-A, among others, have reported selling nearly twice as much poultry in July and August over a year ago, while McDonald’s, known primarily for its chicken nuggets, saw its chicken sales slump.

“We did go a little bit the opposite way on chicken,” chief financial officer Kevin Ozan told Wall Street analysts on an earnings call Tuesday.

The fast-food chain said same-store sales globally grew 5.9 percent in the third quarter, beating expectations for growth of 5.4 percent. But in the US, where fried chicken reigned supreme, comparable store sales increased just 4.8 percent — below growth of 5.7 percent in the previous quarter and below expectations for 5.4 percent growth.

Customer traffic at McDonald’s US stores, which have grown more slowly than its overseas eateries, declined, management said on the call without disclosing by how much.

The company also missed Wall Street’s profit estimates for the first time in two years due in part to a 2 percent rise in operating costs to $3 billion. The company reported earnings of $1.6 billion, or $2.11 per share, on sales of $5.4 billion. Analysts had been expecting earnings of $2.21 cents a share, adjusted for one-time costs, on sales of $5.5 billion.

It’s not just chicken that has US customers turning away from McDonald’s, restaurant analyst Mark Kalinowski told The Post. The fast food chain known for its golden arches is also behind when it comes to the fake-meat craze, driven by products that taste strikingly like meat produced by Impossible Foods and Beyond Meat, Kalinowski said.

Rival Burger King, for example, saw its sales jump by 6 percent in the third-quarter — driven in good part by a new plant-based burger dubbed Impossible Whopper, according to an analysis by investment research firm, Cowen.

McDonald’s has been testing a plant burger with Nestle in Germany and a Beyond Meat burger in Canada, where 28 franchises are selling it.

“We’re interested in this, clearly,” McDonald’s management said on the call. “But it’s very early days.”

McDonald’s shares closed down 5.04 percent to $199.27 a share Tuesday.