raptor finds the minimal travel time and/or earliest arrival time for all
stop_times with journeys departing from
raptor(stop_times, transfers, from_stop_ids, departure_time_range = 3600, max_transfers = NULL, keep = "all")
A (prepared) stop_times table from a gtfs feed. Prepared means
that all stop time rows before the desired journey departure time
should be removed. The table should also only include departures
happening on one day. Use
Transfers table from a gtfs feed. In general no preparation is needed.
Atomic char vector with stop_ids from where a journey should start
All departures from the first departure of
stop_times (not necessarily a from_stop) within
Maximum number of transfers allowed, no limit (NULL) as default.
One of c("all", "shortest", "earliest"). By default
A data.table with travel times to all stop_ids reachable from
and their corresponding journey departure and arrival times.
With a modified Round-Based Public Transit Routing Algorithm
(RAPTOR) using data.table earliest arrival times for all stops are calculated. If two
journeys arrive at the same time, the one with the later departure time and thus shorter
travel time is kept. By default, all journeys within
departure_time_range that arrive
at a stop are returned in a table. Journeys are defined by a departure stop_id, a
departure, arrival and travel time. Note that the exact journeys (with each intermediate
stop and route id for example) is not returned.
For most cases
stop_times needs to be filtered as it should only contain
trips happening on a single day and departures later than a given journey
start time (see
The algorithm scans all trips until it exceeds
max_transfers or all trips
stop_times have been visited.
nyc_path <- system.file("extdata", "google_transit_nyc_subway.zip", package = "tidytransit") nyc <- read_gtfs(nyc_path, local=TRUE) # you can use initial walk times to different stops in walking distance (arbitrary example values) stop_ids_harlem_st <- c("301", "301N", "301S") stop_ids_155_st <- c("A11", "A11N", "A11S", "D12", "D12N", "D12S") walk_times <- data.frame(stop_id = c(stop_ids_harlem_st, stop_ids_155_st), walk_time = c(rep(600, 3), rep(410, 6)), stringsAsFactors = F) # Use journeys departing after 7 AM with arrival time before 11 AM on 26th of June stop_times <- filter_stop_times(nyc, "2018-06-26", 7*3600, 9*3600) # calculate all journeys departing from Harlem St or 155 St between 7:00 and 7:30 rptr <- raptor(stop_times, nyc$transfers, walk_times$stop_id, departure_time_range = 1800, keep = "all") # add walk times to travel times rptr <- left_join(rptr, walk_times, by=c("journey_departure_stop_id" = "stop_id")) rptr$travel_time_incl_walk <- rptr$travel_time + rptr$walk_time # get minimal travel times (with walk times) for all stop_ids shortest_travel_times <- setDT(rptr)[order(travel_time_incl_walk)][, .SD, by = "stop_id"] hist(shortest_travel_times$travel_time, breaks = 360)