Vision Zero Visualization Blog Post Gist

Vision Zero - Mapping 1

# Load NYC map
# Since this line actually run a query on Google Maps, 
# You might want to save this map as RData for furture use
# If you don't know how to do it, please check save() and load() functions
# in the comment line below
nyc_map <- get_map(location = find_map_cent(mvc_count$LON,
                                            mvc_count$LAT),
                   zoom = 11)
# save(nyc_map, file = 'nyc_map.RData')
# load('nyc_map.RData')

# Accident count by location
mvc_count <- work_dt %>%
  filter(!(is.na(LATITUDE) | is.na(LONGITUDE))) %>%
  mutate(LAT = round(LATITUDE, 2),
         LON = round(LONGITUDE, 2)) %>%
  group_by(LAT, LON) %>%
  summarise(N = n())

# Top deaths by location
mvc_dth <- kill_dt %>%
  filter(!(is.na(LATITUDE) | is.na(LONGITUDE))) %>%
  filter(grepl('PERSONS', KILLED)) %>%
  mutate(LAT = round(LATITUDE, 2),
         LON = round(LONGITUDE, 2)) %>%
  select(KILLED_V, LAT, LON) %>%
  group_by(LAT, LON) %>%
  summarise(KILLED_V = sum(KILLED_V)) %>%
  arrange(desc(KILLED_V)) %>%
  # table(mvc_sum$KILLED_V)
  #   1   2   3   4   5 {}  6   7   8  10 
  # 231 121  50  17  13 {}  8   4   2   1
                      # ^ Break here
  filter(KILLED_V >5)

# Mapping accident counts
ggmap(nyc_map, extent = 'device') +
  geom_point(data = mvc_count, alpha = .5,
             aes(x = LON, y = LAT, color = N, size = N)) +
  scale_color_gradient(low = 'white', high = 'red') +
  theme(legend.justification=c(1,1), legend.position=c(.95,.95),
        legend.background = element_rect(color = 'black',
                                         fill = alpha('white', 0.8)),
        legend.title = element_blank()) +
  guides(size = FALSE) +
  ggtitle('Accident Frequencies by Location')