The 34-mile Camden-to-Trenton light rail service recorded 145,860 trips in September. That's the lowest monthly ridership tally since May, when the line carried 126,814 fares.

The line registered 170,699 trips in July and 160,645 in August.

NJ Transit officials trace the midsummer peak to heavy ridership on the Fourth of July and the vacation period that followed.

They attribute the drop in September to the closing of the state aquarium on the Camden Waterfront, which proved to be a major destination for River LINE riders, and the reopening of area schools, depriving the line of some excursion trips.

"The seasonality of ridership is not surprising," said Dan Stessel, a spokesman for NJ Transit, noting that it contains a "large leisure component."

The controversial, billion-dollar line opened March 14.

In the beginning, ridership was heavier on weekends than during the week.

That changed once school let out and average weekday ridership now exceeds the average on both Saturday and Sunday.

NJ Transit officials estimate that ridership on weekdays now is split between commuters and excursion riders.

Commuters and excursion riders alike praise the line for its comfort, cleanliness and efficiency.

Timothy Peters, a Palmyra resident, said he's been taking the line to work in Trenton for six months now and found it a "very positive" experience.

"I'm a committed customer," Peters said.

Weekday ridership on the River LINE has grown dramatically since its debut.

Average weekday passengers trips have increased 59 percent since the first week of service in March, from 3,290 trips to 5,229 trips, the agency said in a statement released Monday.

The statement also noted that monthly pass sales were 38 percent higher than in June, an indicator of rising commuter use.

The agency sold 324 monthly passes for the River LINE in September.

The agency also sold 96 monthly passes good for joint ridership on the River LINE and other NJ Transit rail lines, including the train that runs from Trenton to New York, and 102 passes good for both buses and the light rail line.

In September, when the River LINE passed its six-month milestone, NJ Transit officials said the line had reached an average weekday ridership of 5,679 trips for the last week of August. Officials hailed the number as close to the 5,900 trips per day forecast for the line's first year of operation.

Figures released Monday show the number of weekday trips declined to 5,229 for the month of September.

The original projections for the controversial line, used to justify its construction, were for 9,300 daily trips the first year, rising to 16,300 by the time the line was 20 years old.

A new study done last year revised the projections downward to 5,900 trips the first year and 9,100 after 10 years.