Subway is redesigning its menu

New York(CNN Business) Subway is launching a new menu, and it's the most extensive makeover in the company's nearly 60-year history.

The main appeal of the sandwich chain is that people can make their own custom sandwiches. Yet the seemingly limitless combinations slowed down the speed of the lines at its restaurants.

Subway's new menu is aimed at streamlining those choices. Beginning Tuesday, customers will be greeted with a refreshed menu board in its roughly 21,000 US restaurants featuring 12 sandwiches in what it's calling the "Subway Series" menu.

The new, more neatly organized menu is divided in to four categories (Cheesesteaks, Italianos, Chicken and Clubs) consisting of three sandwiches each. All 12 sandwiches are new to the menu, with some essentially replacing previous versions with new names and slight tweaks. For example, the Meatball Marinara sandwich is now called The Boss with newly added melted mozzarella cheese.

Subway says people can order the sandwiches by their new names or by their assigned numbers. And the sandwiches can be made with bread, wrap or have its topping placed on a bed of lettuce. Customers, of course, can still choose custom options if they prefer.

"Complementary flavors and an expertly crafted balance of proteins, cheese, sauces and fresh vegetables are designed to maximize taste and crave," the chain said in a press release, adding that the changes allow customers "to explore new options beyond their beloved build-your-own customization."

Last year, Subway rolled out an updated menu including 20 new and refreshed ingredients for some of its breads and meats. For example, Subway began slicing its turkey and ham more thinly and brought back past items like rotisserie-style chicken and roast beef. The refreshed menu was part of its "Eat Fresh Refresh" ad campaign, which will be tweaked to promote the new "Subway Series" menu.

Sales at Subway's US locations have been falling in recent years, according to the research firm Technomic. System-wide sales at Subway's US locations were $12.3 billion in 2013, which was its best year of the past 15 years. in 2021, sales slumped to $9.4 billion, according to Technomic's analysis. The number of locations has declined for the fifth year in a row to 20,746 per Subway's website.

Subway is a privately held company and does not publicly disclose sales figures.