RAILSIM plays a leading role in achieving successful operations like those Caltrain reported (below) following the first-week of its new Baby Bullet express train service, which was launched on June 14, 2004.

Caltrain services continue to be bolstered by the Baby Bullet, which has been credited with the lions' share of Caltrain's 27.6% increase in commuter rail riders in 2005, something of a surprise since fare increases raised riders' costs by more than 17% during the year.

With a service area that falls within the fifth largest metropolitan area in the U.S., Caltrain experienced a growth in ridership of nearly 50% between 1992 and 2000.  Service expansion was necessary to accommodate that growth, and also to lure more drivers off the increasingly crowded highways and into trains.

Caltrain planned to add a new express (Baby Bullet) train service on top of the existing blend of local, skip-stop and limited-express train services, on a double-track rail line having a high volume of traffic on each of the two tracks.  To accomplish the implementation of the new express service, Caltrain added pairs of passing tracks at two sections of its main line, and opened two new stations at Lawrence and Bayshore.  The resulting Baby Bullet express service comprises a 48-mile route, on which trains stop at only four or five locations.  While Zone Express trains typically travel between San Jose and San Francisco in about 90 minutes and All-Stops Local trains typically take 102 minutes, the Baby Bullet run averages 57 minutes.

RAILSIM supported every stage of this broad operational and infrastructure project, which began with the development of a detailed simulation model of Caltrain's entire rail network, including rail alignment, physical plant, signal control system, equipment, and operating plan (train schedules) information.  RAILSIM simulations then:

• Analyzed in detail the many stations where its “Hold Out” Rule is in effect.  RAILSIM Network Simulator mimics the Caltrain-specific “Hold-Out” rule in force at some station stops, such that if a train is already in the Station, a second train approaching the same Station will stop short of the platform area (or “hold out”) until the train already in the Station begins its departure,

• Quantified signal-system headways and throughput characteristics,

• Determined the required physical-plant improvements necessary to properly handle the future mix and volumes of express and local trains. (These capital items included station improvements, determining the optimum locations and lengths of the new passing tracks, defining necessary signal and interlocking improvements, etc.), and

• Tested proposed physical plant upgrades and future timetable schedules, alerting project personnel of points where refinements must be made to result in final operations that reflected Caltrain's service goals.