day-26-transport.R

# Day 26: Transport - US Electric Power Transmission Lines
# Visualizing America's invisible highway: 700,000+ miles of power lines
# Dynamic line widths by voltage class, glowing effect for the energy flow

library(mapgl)
library(sf)
library(dplyr)

# Load transmission lines from HIFLD (Homeland Infrastructure Foundation-Level Data)
# This is a large dataset - we'll use direct URL for the GeoJSON
transmission_url <- paste0(
 "https://services2.arcgis.com/FiaPA4ga0iQKduv3/arcgis/rest/services/",
 "US_Electric_Power_Transmission_Lines/FeatureServer/0/query?",
 "outFields=*&where=1%3D1&f=geojson"
)

# Read and process
lines <- st_read(transmission_url)

# Clean up voltage classes for visualization
lines <- lines |>
 mutate(
   voltage_category = case_when(
     VOLT_CLASS == "UNDER 100" ~ "Under 100 kV",
     VOLT_CLASS == "100-161" ~ "100-161 kV",
     VOLT_CLASS == "220-287" ~ "220-287 kV",
     VOLT_CLASS == "345" ~ "345 kV",
     VOLT_CLASS == "500" ~ "500 kV",
     VOLT_CLASS == "735 AND ABOVE" ~ "735+ kV",
     VOLT_CLASS == "DC" ~ "DC",
     TRUE ~ "Unknown"
   ),
   # Numeric for sizing
   voltage_rank = case_when(
     VOLT_CLASS == "UNDER 100" ~ 1,
     VOLT_CLASS == "100-161" ~ 2,
     VOLT_CLASS == "220-287" ~ 3,
     VOLT_CLASS == "345" ~ 4,
     VOLT_CLASS == "500" ~ 5,
     VOLT_CLASS == "735 AND ABOVE" ~ 6,
     VOLT_CLASS == "DC" ~ 5,
     TRUE ~ 1
   )
 )

# Electric color palette - from dim to blazing
electric_colors <- c(
 "#1a1a2e", # dim - unknown/low
 "#4a00e0", # violet - under 100
 "#8e2de2", # purple - 100-161
 "#00d4ff", # cyan - 220-287
 "#00ff88", # green - 345
 "#ffdd00", # yellow - 500
 "#ff6600"
)

# Build the map with glowing transmission lines
maplibre(
 style = maptiler_style("backdrop", variant = "dark"),
 center = c(-98.5, 39.5),
 zoom = 4,
 pitch = 0
) |>
 # Outer glow layer - creates the electric aura
 # Glow scales with zoom to avoid artifacts when zoomed out
 add_line_layer(
   id = "transmission-glow",
   source = lines,
   line_color = interpolate(
     column = "voltage_rank",
     values = c(1, 2, 3, 4, 5, 6),
     stops = c("#4a00e0", "#8e2de2", "#00d4ff", "#00ff88", "#ffdd00", "#ff6600")
   ),
   line_width = interpolate(
     property = "zoom",
     values = c(3, 6, 10),
     stops = c(2, 6, 14)
   ),
   line_blur = interpolate(
     property = "zoom",
     values = c(3, 6, 10),
     stops = c(1, 3, 6)
   ),
   line_opacity = interpolate(
     property = "zoom",
     values = c(3, 5, 7),
     stops = c(0.2, 0.3, 0.4)
   )
 ) |>
 # Core line layer - the actual transmission line
 add_line_layer(
   id = "transmission-lines",
   source = lines,
   line_color = interpolate(
     column = "voltage_rank",
     values = c(1, 2, 3, 4, 5, 6),
     stops = c("#6366f1", "#a855f7", "#22d3ee", "#4ade80", "#facc15", "#fb923c")
   ),
   line_width = interpolate(
     property = "zoom",
     values = c(3, 6, 10),
     stops = c(0.5, 1.5, 4)
   ),
   line_opacity = 0.9,
   tooltip = concat(
     "<div style='background: #0a0a14; color: #e0e0e0; padding: 12px 16px; ",
     "border-radius: 8px; border: 1px solid rgba(0, 212, 255, 0.4); ",
     "box-shadow: 0 0 15px rgba(0, 212, 255, 0.3); font-family: system-ui;'>",
     "<div style='font-size: 15px; font-weight: 700; color: #00d4ff; margin-bottom: 8px; ",
     "text-shadow: 0 0 8px rgba(0, 212, 255, 0.5);'>",
     get_column("voltage_category"),
     "</div>",
     "<div style='font-size: 12px; line-height: 1.6;'>",
     "<span style='color: #888;'>Type:</span> ",
     get_column("TYPE"),
     "<br><span style='color: #888;'>Status:</span> ",
     get_column("STATUS"),
     "<br><span style='color: #888;'>Owner:</span> ",
     get_column("OWNER"),
     "</div></div>"
   )
 ) |>
 # Title control
 add_control(
   html = paste0(
     "<div style='font-family: -apple-system, BlinkMacSystemFont, \"Segoe UI\", Roboto, sans-serif; ",
     "background: rgba(10, 10, 20, 0.9); padding: 16px 20px; border-radius: 8px; ",
     "border: 1px solid rgba(100, 200, 255, 0.3); box-shadow: 0 0 20px rgba(0, 200, 255, 0.2); ",
     "max-width: 320px;'>",
     "<div style='font-size: 20px; font-weight: 700; color: #00d4ff; margin-bottom: 8px; ",
     "text-shadow: 0 0 10px rgba(0, 212, 255, 0.5);'>",
     "U.S. Power Grid</div>",
     "<div style='font-size: 13px; color: #a0a0a0; line-height: 1.5;'>",
     "Over 700,000 miles of high-voltage transmission lines power America. ",
     "Line brightness and width indicate voltage class.</div>",
     "<div style='font-size: 10px; color: #606060; margin-top: 10px; padding-top: 8px; ",
     "border-top: 1px solid rgba(100, 200, 255, 0.2);'>",
     "Source: Homeland Infrastructure Foundation-Level Data (HIFLD)</div>",
     "</div>"
   ),
   position = "top-left"
 ) |>
 # Voltage legend
 add_legend(
   legend_title = "Voltage Class",
   values = c("Under 100 kV", "100-161 kV", "220-287 kV", "345 kV", "500 kV", "735+ kV"),
   colors = c("#6366f1", "#a855f7", "#22d3ee", "#4ade80", "#facc15", "#fb923c"),
   type = "categorical",
   position = "bottom-left",
   width = "160px"
 ) |>
 add_navigation_control(position = "top-right") |>
 add_fullscreen_control(position = "top-right")