Introduction to mobdb

Introduction

mobdb is your first stop to analyzing transit in R. It helps you find and download GTFS feeds from the Mobility Database, which contains information for about 4000+ transit and shared mobility feeds worldwide.

After discovering and downloading feeds with mobdb, you can:

Analyze feeds with tidytransit - calculate frequencies, travel times, and visualize routes
Edit feeds with gtfstools - filter, merge, and validate feeds
Read/Write feeds with gtfsio - fast I/O operations

Installation

Install mobdb from GitHub:

# install.packages("pak")
pak::pak("jasonad123/mobdb")

Authentication

The Mobility Database API requires authentication. You’ll need to:

Go to https://mobilitydatabase.org/
Sign in (or create a free account)
Go to your account settings
Generate an API refresh token
Store it in your R environment

library(mobdb)

# Shortcut to launch the Mobility Database in your browser
mobdb_browse()

# Set your API refresh token (do this once)
# mobdb_set_key("your-refresh-token-here")

# Check if authentication is configured
mobdb_has_key()
#> [1] TRUE

Tip: Store your token in your .Renviron file to avoid entering it each session:

usethis::edit_r_environ()
# Add this line:
# MOBDB_REFRESH_TOKEN=your-refresh-token-here

Basic Workflow: Discovery → Download → Analysis

Step 1: Discover feeds

Find GTFS feeds using various search criteria:

# Find all feeds in California
ca_feeds <- feeds(
  country_code = "US",
  subdivision_name = "California",
  data_type = "gtfs"
)

# View results
head(ca_feeds)
#> # A tibble: 6 × 10
#>   id       data_type status provider     feed_name location...

# Search by provider name
bart_feeds <- feeds("BART")
bart_feeds

Step 2: Download feeds

Download a specific feed by ID or search term:

# Download by feed ID (Bay Area Rapid Transit)
bart <- download_feed("mdb-53")

# Or search and download in one step (use full name for better results)
bart <- download_feed(provider = "Bay Area Rapid Transit")

# The result is a gtfs object (from tidytransit)
class(bart)
#> [1] "tidygtfs" "gtfs"     "list"

names(bart)
#> [1] "agency" "calendar" "calendar_attributes" "calendar_dates" "directions" ...

Step 3: Analyze feeds with tidytransit

Now that you have the feed, use tidytransit for analysis:

library(tidytransit)

# Validate the feed
validation <- validate_gtfs(bart)
summary(validation)

# Calculate stop frequencies
stop_freq <- get_stop_frequency(bart)
head(stop_freq)

# Calculate route frequencies
route_freq <- get_route_frequency(bart)
head(route_freq)

# Convert to spatial features
bart_sf <- gtfs_as_sf(bart)
plot(bart_sf$stops)

Common use cases

Finding Feeds by Location

# Find feeds in a specific municipality
seattle_feeds <- feeds(municipality = "Seattle", data_type = "gtfs")

# Find feeds in a country
canada_feeds <- feeds(country_code = "CA", data_type = "gtfs")

# Combine filters
bc_feeds <- feeds(
  country_code = "CA",
  subdivision_name = "British Columbia",
  status = "active",
  data_type = "gtfs"
)

Working with Multiple Feeds

# Get feeds for several cities
agencies <- c("TriMet", "King County Metro", "TransLink Vancouver")
feeds_list <- lapply(agencies, function(agency) {
  feeds <- feeds(provider = agency, data_type = "gtfs")
  if (nrow(feeds) > 0) {
    download_feed(feeds$id[1])
  }
})

# Analyze each feed with tidytransit
library(tidytransit)
frequencies <- lapply(feeds_list, function(gtfs) {
  if (!is.null(gtfs)) get_stop_frequency(gtfs)
})

Complete Example Workflow

Here’s a complete example from discovery to analysis:

library(mobdb)
library(tidytransit)
library(ggplot2)
library(tidyverse)
library(sf)

# 1. DISCOVER: Find feeds in Vancouver, BC, Canada
vancouver_feeds <- feeds(
  provider = "TransLink",
  municipality = "Vancouver",
  country_code = "CA",
  data_type = "gtfs"
)

# 2. DOWNLOAD: Get the sixth feed (TransLink)
translink <- download_feed(vancouver_feeds$id[1])

# 3. VALIDATE: Check feed quality (tidytransit)
validation <- validate_gtfs(translink)
print(validation)

# 3a. VALIDATE (another way): Check feed quality (using the MobilityData report)
vancouver_datasets <- mobdb_datasets(vancouver_feeds$id[1])
feed_report <- get_validation_report(vancouver_datasets)
print(feed_report)

# 4. ANALYZE: Calculate AM route frequencies (tidytransit)
am_route_freq <- get_route_frequency(translink,
                                     start_time = 6 * 3600, end_time = 10 * 3600)
head(am_route_freq) %>%
  knitr::kable()

# get_route_geometry needs a gtfs object that includes shapes as simple feature data frames
translink <- gtfs_as_sf(translink)
routes_sf <- get_route_geometry(translink)

routes_sf <- routes_sf %>%
  inner_join(am_route_freq, by = "route_id")

# 5. VISUALIZE: Plot routes with (tidytransit + ggplot2)
# convert to an appropriate coordinate reference system
routes_sf_crs <- sf::st_transform(routes_sf, 26910)

routes_sf_crs %>%
  filter(median_headways < 10 * 60) %>%
  ggplot() +
  geom_sf(aes(colour = as.factor(median_headways))) +
  labs(color = "Headways") +
  geom_sf_text(aes(label = route_id)) +
  theme_bw()

routes_sf_buffer <- st_buffer(routes_sf, dist = routes_sf$total_departures / 1e6)

routes_sf_buffer %>%
  ggplot() +
  geom_sf(colour = alpha("white", 0), fill = alpha("blue", 0.5)) +
  theme_bw()

mobdb is just the first stop, not the end of the route when it comes to transit and transportation on R. Here are some other packages in the R ecosystem for analyzing GTFS.

tidytransit: A tool to read and analyze GTFS feeds
gtfstools: Edit and validate feeds
gtfsio: Fast I/O operations like saving GTFS back to ZIP files

Once you have GTFS files or GTFS objects, you can perform some pretty interesting analysis with other tools like:

R5r: A wrapper for the R5 routing engine, to perform travel time and access analysis
dodgr: Distances on Directed Graphs in R