September was a record-setting month for the expanding Los Angeles County Metropolitan Transportation Authority (Metro) system.

The average weekday ridership of 92,120 boardings set a record for the Metro Blue Line. Ridership on the Metro Orange Line, which now includes boardings from the new four-mile extension to Chatsworth, soared to 31,787. After opening two new stations in June, the new Metro Expo Line, which reported 11,347 boarding in its May start-up reports, surpassed 20,000 boardings.

Metro officials point to the roiling fluctuations of gas prices as a major influence on public transportation ridership. But as the economy continues to improve, other factors weigh in on the upward trend, including efforts to combat congestion, a concern for the environment, social media technology, and a new generation that chooses bicycling and public transportation over expensive car ownership.

Since September 2011, ridership on Metro's bus system held steady with a slight increase of 0.8%, averaging more than 1.18 million boarding passengers on an average weekday in September.

Overall, Metro Rail ridership showed a 12% gain over the previous 12 months, totaling 357,096 average weekday boardings on the entire 87.7-mile system. The Metro Blue Line carried an average of 92,120 customers, the Metro Green Line recorded 46,393, the Metro Gold Line logged 41,987, and the Metro Red/Purple Line averaged 155,940 weekday boardings in September.