OpenInterstate Reachability

Proximity is a poor predictor of drivability around highway interchanges: a gas station 200 meters from an exit can be a five-minute detour, or unreachable from that side of the highway. This project computes real driving routes for every exit-place pair in an OpenInterstate release and publishes the scores as open data.

Get the data

Each scoring run publishes a score-* release on the releases page, pinned in its notes to the exact OpenInterstate release it scored:

gh release download --repo tldev/openinterstate-reachability --pattern reachability.csv

• reachability.csv holds OSRM driving distance and duration, a reachable flag, a 0 to 100 score, and a confidence value per exit-place pair. Rows join back to the source release through exit_id and place_id.
• osrm_snap_hints.csv holds cached road-network snap points that make later runs incremental.

Every column is documented in datapackage.json (Data Package standard) and rendered at https://openinterstate.org/schema. The data is OpenStreetMap-derived and published under ODbL 1.0.

Scoring model

OSRM computes a driving route for each pair. The score starts at 100 and subtracts a route-distance penalty (up to 70 points) and an exit-offset penalty (up to 20 points); unreachable pairs score 0. Confidence steps down from 0.95 as route distance grows.

How it runs

One GitHub Actions workflow (score.yml) orchestrates two AWS Batch jobs with no persistent infrastructure:

1. osm-build (on-demand EC2): downloads the US PBF, filters it, and builds the OSRM dataset onto an ephemeral EBS volume. This takes hours and is not resumable, so it runs on-demand.
2. score (spot EC2, three retries): mounts the volume, fetches the OpenInterstate release, scores every exit-place pair, and uploads the CSV. Scoring is resumable through snap hints, so spot interruptions are cheap.

The volume is deleted when the run finishes. A successful run publishes the score-* release and sends a reachability-release repository_dispatch to the repo named by the DOWNSTREAM_DISPATCH_REPO variable, when set.

Triggers: a repository_dispatch of type oi-release, or a manual workflow_dispatch that can pin oi_release_tag or reuse an existing OSRM volume via ebs_volume_id.

Run your own

1. Deploy the CloudFormation stack: scripts/setup-aws.sh --email <alarm-email> (auto-detects the default VPC, or pass --vpc and --subnets).
2. Set the AWS_ACCOUNT_ID and AWS_ROLE_ARN repository secrets from the printed outputs.
3. Optionally set the DOWNSTREAM_DISPATCH_REPO repository variable and a CROSS_REPO_TOKEN secret to notify a downstream consumer.
4. Run the Reachability Scoring Pipeline workflow.

The stack includes Batch job timeouts, a workflow timeout, and a monthly CloudWatch billing alarm.