Portland–Lewiston Interurban

Service was interrupted during the spring of 1916 by snowmelt freshets causing extensive washouts between Gray and West Falmouth. Fifty dollars was stolen when the last daily train from Lewiston to Portland was robbed at Fairview Junction on 18 March 1917. Heavy snow collapsed the roof of the Gray car barn on 11 February 1918, but it was rebuilt. Express car 32 and Gladiolus suffered repairable minor damage in a slow head-on collision in Falmouth on 1 March 1918. Androscoggin Electric Company merged into Central Maine Power in 1919. The blizzard of 6 March 1920 caused cancellation of many Maine trains including the PLI cars. The Maine Statehood Centennial Exposition in Portland on 5 July 1920 created the PLI's heaviest daily passenger load. Coach-smoker Maine was purchased for the Exposition, and the box express cars were temporarily fitted with benches to carry all the passengers.

Two extra cars carrying the Auburn high school basketball team and students to a Portland game collided at Deering Junction on 24 January 1924. The following Maine rammed the leading Azalea as it slowed in heavy fog. There were no serious injuries, but the game was cancelled and both cars required repairs. Although the other concrete bridges proved durable, the Presumpscot River bridge was weakened by paper mill waste and required replacement by a steel span in 1927. In September 1929 the competing Androscoggin and Kennebec (A&K) electric railway abandoned its parallel line south of Lewiston in favor of a trackage rights agreement with the PLI. When the A&K completely abandoned its service east of Lewiston to Augusta in July 1932, PLI made an agreement to transfer express at Lewiston to Hodgdon's Motor Express Company highway trucks for continued service to Augusta.

As increasing numbers of riders left PLI cars for automobiles through the 1920s and Great Depression, interurban service ended on 29 June 1933 and the rails were lifted in 1934. The Danville substation was retained by Central Maine Power Company, but the Gray and West Falmouth substations were sold as residential dwellings, and the Lewiston car barn was converted to a Red and White food store. Much of the right-of-way between Portland and West Falmouth was used for the Maine Turnpike; but a portion of the right-of-way through Gray was on planning to be restored for use by the Maine Narrow Gauge Railroad Museum, but those plans were since abandoned and the museum remains in Portland. The interurban car Narcissus has been preserved at the Seashore Trolley Museum.

Summer-season construction began in 1910 including ten reinforced concrete bridges. The longest was a 200-foot (61 m) span over the Presumpscot River There was a 100-foot (30 m) span over the Little Androscoggin River in Auburn and a span of similar length near West Falmouth. Approximately 30 miles (48 km) of 70-pound (32 kg) steel rail was laid in 33-foot (10 m) lengths over private right-of-way connecting segments of trackage rights over Portland, Lewiston, and Auburn city streetcar lines. Scheduled interurban service began on 7 July 1914. At Gray, odd-numbered northbound trains took a siding to cross even-numbered southbound trains on the following route from north to south:

Lewiston 210 feet (64 m) by 75 feet (23 m) brick passenger terminal and 4-track car barn and repair shop on Middle Street

Fairview Junction with the Auburn streetcar line

Sadler's siding