Ridership has grown steadily on the 33km line since the first phase opened in 2000, and over the last seven years passenger numbers have doubled to more than 45,000 per day.

Under the joint project by LRV supplier Kinkisharyo International, NJ Transit, and the line's operator Twenty-First Century Rail Corporation, one of the existing vehicles has been lengthened by 11m to 39m, increasing seating capacity from 68 to 102 seats and providing a significant increase in standing room.

NJ Transit says that by utilising existing resources and spare equipment, the conversion is estimated to cost significantly less than purchasing new standard LRVs.

The extended vehicle is now undergoing a six-month trial on the Hudson-Bergen line, during which time it will operate on all three routes. NJ Transit will carry out a full evaluation of the project before deciding whether to lengthen further vehicles.