US 66 through Arizona to California. In 1940, the novel was adapted by 20th Century Fox into a movie starring actor Henry Fonda as Tom Joad. Several scenes in the movie were filmed along US 66 in Arizona, including scenes where the family crossed the Arizona–New Mexico state line near Lupton and the Old Trails Bridge over the Colorado River in Topock. The golden age During the first three years of American involvement in World War II, civilian travel on US 66 declined greatly. In 1941, 17,600 cars a month were traveling westbound on the highway between New Mexico and California. By 1942, the number had decreased to 13,680 cars a month, then dropped to 7,040 cars a month by May 1943. This was largely because gasoline available to civilians was heavily rationed for the war effort and harder to come by. However, military traffic heavily used the highway during this time as several military installations were located near US 66. One such installation was the Navajo Army Depot in Bellemont. The military often transported troops, weapons and supplies. Despite the decline in civilian travel, people leaving the east coast to find wartime work in California often took US 66. At the end of the war, many of the people who had gone to California for work returned home to the east coast on US 66. The eastward migration caused US 66 traffic to increase from record low numbers to the highest volume of traffic the highway had seen up to that point. By October 1945, 700–800 cars a day were traveling down US 66 in Arizona and some cars had as many as 17 people inside them. At night, there were up to 137 cars parked on the side of the road, so the occupants could sleep during the night. Drivers often traveled down the highway at dangerous speeds or drove for long periods, becoming fatigued. This, in tandem with increasing traffic, caused the number of fatal car accidents to rise exponentially. Between January and October 1945, 198 people were killed in car accidents on US 66. As a result, the Arizona Highway Patrol had to greatly increase the number of patrolmen on US 66 to crack down on reckless driving. In 1945, the Santa Fe Railway constructed a new rail bridge over the Colorado River in Needles and Topock, upstream from the Old Trails and Red Rock Bridges.