map highways in Switzerland - France

map_highways.R

# map highways in Switzerland - France 

# load packages
library(tidyverse)
library(sf)
library(osmdata)
library(mapview)

# define zone of interest
lonmin <- 6
lonmax <- 8.5
latmin <- 46.1
latmax <- 47.7
bb <- st_sf(a = 1:2, geom = st_sfc(st_point(c(lonmin,latmin)), st_point(c(lonmax,latmax))))
st_bbox(bb)

# get osm data
x <- bb %>% 
  st_bbox() %>%
  opq() %>%
  add_osm_feature("route", value = "road") %>%
  osmdata_sf()

# pick lines
osm <- x$osm_lines %>%
  st_transform(crs = 21781)

# clean up road
routes <- osm %>% 
filter(highway %in% c('motorway', 'motorway_link', 'trunk', 'trunk_link',
                      'primary', 'primary_link',
                      'secondary', 'secondary_link',
                      'tertiary', 'tertiary_link', 'unclassified')) %>%
  mutate(type = as.factor(highway)) %>%
  select(name, hgv, type, lanes) %>%
  mutate(type = droplevels(type)) %>%
  mutate(road_type = case_when( 
    type %in% c('motorway', 'motorway_link', 'trunk', 'trunk_link') ~ "aut", # stable territory in winter
    type %in% c('primary', 'primary_link') ~ "ppa", 
    type %in% c('secondary', 'secondary_link') ~ "reg",
    type %in% c('tertiary', 'tertiary_link', 'unclassified') ~ "loc"))

# visualize roads
ggplot() + 
  geom_sf(data = routes, lwd = 0.1, colour = "blue")

# get highways
highways <- routes %>% 
  mutate(road_type = as_factor(road_type)) %>% 
  filter(road_type == "aut")
         
# visualize highway
ggplot() + 
  geom_sf(data = highways, lwd = 0.1) 

# locate highways on a map of Europe - interactively
mapview(highways)