metra（metra 搜索）

Chicago Metra Commuter Rail

Real-time Chicago Metra commuter rail data — train arrivals (GTFS-RT protobuf), vehicle positions, service alerts, schedule info, and fare calculation for all 11 Metra lines serving the six-county northeastern Illinois region. Requires a free API key for all feeds.

When to Use

• User asks about Metra, Chicago commuter rail, or commuter trains in Chicago
• User asks "when is the next train" in a Chicago suburban context
• User mentions specific Metra lines: BNSF, UP-N, UP-NW, UP-W, MD-N, MD-W, ME (Metra Electric), RI (Rock Island), NCS, HC (Heritage Corridor), SWS (SouthWest Service)
• User mentions specific Metra stations: Union Station, Ogilvie, Millennium Station, LaSalle Street, Naperville, Aurora, Downers Grove, Evanston, Highland Park, etc.
• User asks about Metra service alerts, delays, or construction
• User asks about Metra fares, zones, monthly passes, Ventra
• User asks about Chicago train schedules (distinguish from CTA "L" trains — Metra is commuter rail)

When NOT to Use

• User asks about CTA trains (the "L"), CTA buses, or Pace buses — those are separate systems
• User asks about Amtrak long-distance trains at Union Station

Data Sources

Metra uses standard GTFS-RT protobuf feeds served from a single base URL with Bearer token authentication. No proprietary extensions — clean standard GTFS-RT.

GTFS Realtime Feeds (Protobuf, requires METRA_API_KEY)

Get a free key at: https://metra.com/developers

Base URL: https://gtfspublic.metrarr.com

Authentication: Authorization: Bearer {METRA_API_KEY} header.

Data updates every 30 seconds. No need to poll more frequently.

GTFS Static Feed

Static schedule updates regularly (sometimes within 24 hours). New scheduled updates publish at 3:00 AM.

Important Notes from Metra

• If realtime data is unavailable for a trip, assume the static schedule is correct
• Vehicle positions may drop when trains are underground or at terminals (GPS loss)
• Trip updates may be provided hours in advance for annulled or added trains
• If an alert is in the feed, it's active; if it's not, it's no longer active (regardless of active_period)

Implementation

Script: scripts/metra.mjs

Main entry point. Supports these commands:

# Train arrivals
node scripts/metra.mjs arrivals --station "Union Station"
node scripts/metra.mjs arrivals --station "Naperville" --line BNSF
node scripts/metra.mjs arrivals --station "Ogilvie"
node scripts/metra.mjs arrivals --station "Millennium Station" --line ME

# Vehicle tracking
node scripts/metra.mjs vehicles --line BNSF
node scripts/metra.mjs vehicles --line UP-N
node scripts/metra.mjs vehicles --line ME

# Service alerts
node scripts/metra.mjs alerts
node scripts/metra.mjs alerts --line BNSF
node scripts/metra.mjs alerts --line RI

# Routes and stops
node scripts/metra.mjs routes
node scripts/metra.mjs stops --search "downers grove"
node scripts/metra.mjs stops --line BNSF
node scripts/metra.mjs stops --near 41.8781,-87.6298
node scripts/metra.mjs route-info --line UP-NW

# Fares
node scripts/metra.mjs fares
node scripts/metra.mjs fares --from "Union Station" --to "Naperville"

# Schedule
node scripts/metra.mjs schedule --station "Naperville"
node scripts/metra.mjs schedule --station "Ogilvie" --line UP-N

# Maintenance
node scripts/metra.mjs refresh-gtfs

Setup: API Key

All Metra feeds require authentication:

1. Register for a free key at https://metra.com/developers
2. Set environment variable: METRA_API_KEY

Setup: GTFS Static Data

On first use, run node scripts/metra.mjs refresh-gtfs to download and extract the static GTFS data (routes, stops, schedules) to ~/.metra/gtfs/. Refresh periodically or when Metra updates their schedule.

Metra Lines Reference

Downtown Terminal Stations

• Chicago Union Station (CUS) — Zone 1 — BNSF, HC, MD-N, MD-W, NCS, SWS
• Ogilvie Transportation Center (OTC) — Zone 1 — UP-N, UP-NW, UP-W
• LaSalle Street Station — Zone 1 — RI
• Millennium Station — Zone 1 — ME

Metra Fares Reference (4-Zone System, effective Feb 2024)

Special Passes:

• Saturday/Sunday/Holiday Day Pass: $7.00 (systemwide)
• Weekend Pass (Ventra app only): $10.00 (systemwide)
• Regional Connect Pass (with Monthly): $30.00 (adds CTA + Pace)
• Onboard Surcharge (cash on train): $5.00

Monthly Passes are valid for unlimited rides on weekdays between selected zones and systemwide on weekends.

Tips for Users

• Metra uses inbound (toward downtown Chicago) and outbound (away from downtown) for directions
• Train numbers matter — Metra riders often know their train by number (e.g., "the 7:42 BNSF" or "Train 1252")
• Different lines use different downtown terminals — always note which terminal
• Peak trains run during rush hours; off-peak and weekend service is less frequent
• If real-time data is unavailable, the schedule command shows static times
• Use --line to filter by specific Metra line code (BNSF, UP-N, etc.)

Error Handling

• If METRA_API_KEY is not set, all commands print a helpful message with the signup URL
• Invalid station names show "No matching station found" with a suggestion to use stops --search
• No real-time data available → fall back to static schedule with a note
• Network errors produce friendly messages
• GPS dropout for vehicle positions → note that train may be underground or at terminal

Response Formatting

When presenting transit info to the user:

• Lead with the most actionable info (next arrival time, active alerts)
• Show line name AND train number (e.g., "BNSF Train 1252 inbound")
• Show times in 12-hour format with AM/PM
• For arrivals: show both real-time ETA and scheduled time when available
• Always note the downtown terminal for the line
• If there are active service alerts for the line being queried, mention them

External Endpoints

All API calls use HTTPS. The API key is passed as a Bearer token in the Authorization header. No other user data is transmitted.

Security & Privacy

• API key required — All GTFS-RT feeds require a free developer key passed as a Bearer token in the Authorization header
• No user data transmitted — Requests contain only the API key; no personal information
• Local storage only — GTFS static data is cached locally at ~/.metra/gtfs/; no data is written elsewhere
• No telemetry — This skill does not phone home or collect usage data
• Input handling — Stop names and route IDs from user input are used only for local filtering, never interpolated into shell commands

Trust Statement

This skill reads publicly available transit data from Metra's official GTFS-RT feeds. The API key is used only for Metra API authentication. The skill does not access, store, or transmit any personal information beyond the API key configured by the user.