Discrepancies between max_walk_dist and max_bike_dist and actual distances travelled during routing

[mvpsaraiva]

The max_walk_dist and max_bike_dist parameters define the max travelling distance to access transit stops or for direct trips in all routing functions. r5r converts those parameters to max walk and bike times under the hood, according to walking and cycling speeds provided.

The issue here is that the conversion is not as straightforward as it used to be, now that R5 takes the city's topography into account. Thus, a trip that is well within max_walk_dist is not retrieved because its adjusted walking time (due to topography) is longer than the pre-calculated walking time considering flat terrain.

Reproducible example:

library("r5r")

# build transport network
data_path <- system.file("extdata/poa", package = "r5r")
r5r_core <- setup_r5(data_path, elevation = "TOBLER", overwrite = T)

# load origin/destination points
points <- read.csv(file.path(data_path, "poa_points_of_interest.csv"))

# inputs
departure_datetime <- as.POSIXct("13-05-2019 14:00:00",
                                 format = "%d-%m-%Y %H:%M:%S")

# a <- capture.output(
  dit <- detailed_itineraries(r5r_core,
                              origins = points[1,],
                              destinations = points[3,],
                              mode = c("WALK", "TRANSIT"),
                              departure_datetime = departure_datetime,
                              max_walk_dist = 1800,
                              max_trip_duration = 30,
                              shortest_path = F)

In the example above, the first trip is 1583 meters long, but it's only retrieved when max_walk_dist is above 1800. If elevation = "NONE" in setup_r5(), max_walk_dist works as expected.

The only solution for this problem that I can think of is to change the parameters to max_walk_time and max_bike_time, because that's how R5 works natively.

[rafapereirabr]

I agree. It would make sense to replace the max_*_dist parameters with max_*_time.

[rafapereirabr]

closed with