Total calls, through July 17: 6,518.Average weekday NextRide calls: 240.5 per day.Average weekend NextRide calls: 213.5 per day.Largest total: 317 on July 16.Smallest total: 152 on June 20.CALLS BY ROUTENo. 4 (Fourth Plain): 1,773.No. 37 (Highway 99/Mill Plain): 1,721.No. 32 (Hazel Dell/Evergreen/Andresen): 867.No. 30 (Burton): 788.No. 44 (Fourth Plain limited): 764.Source: C-TranAbout a month after its launch, C-Tran’s new “NextRide” system appears to be gaining traction. The automated bus-tracking service has fielded more than 6,500 calls since it came online June 20, according to C-Tran.The biggest day so far was Saturday, when NextRide received 317 calls.“As word continues to get out, we certainly expect those numbers to grow,” said Scott Patterson, C-Tran’s public affairs director.Here’s how it works: While waiting at a bus stop, passengers can call C-Tran’s passenger service number, 360-695-0123, to reach NextRide. Enter a four-digit stop ID number posted on the sign, and NextRide will estimate the time until the next bus arrives. If there’s no ID number posted — not all stops have them yet, Patterson said — a series of automated prompts direct callers to find their stop before giving the arrival time of the bus.The system uses GPS tracking devices installed on C-Tran’s fleet a few years ago, keying on bus location and speed to create an arrival estimate. With similar services offered by other transit districts, including Portland’s TriMet, NextRide was a logical step for C-Tran, Patterson said.“We get calls from passengers quite often wondering if their bus is on time,” Patterson said. “It’s more the direction the industry is going, and we knew it would be a highly valued item.”NextRide’s numbers appear to support that. The volume of calls has followed a generally upward trend since the beginning, according to the data.