Regions & corridors
The region argument selects the region. Geofence works for every region, while route and depot require interstate route artifacts, currently built for Travis and the cross-state interstate corridors.
Checking the live list
The table below is the full mode matrix from the catalog. The set of regions actually loaded by a given server is reported by hb.regions(). Check against it before sending.
for r in hb.regions().regions:
print(r.region, r.modes)Mode availability by region
| Region | Geofence | Route | Depot |
|---|---|---|---|
travis | ✅ | - | - |
houston | ✅ | - | - |
sanantonio | ✅ | - | - |
dallas | ✅ | - | - |
sf | ✅ | - | - |
la | ✅ | - | - |
phoenix | ✅ | - | - |
vegas | ✅ | - | - |
sandiego | ✅ | - | - |
sacramento | ✅ | - | - |
philadelphia | ✅ | - | - |
boston | ✅ | - | - |
cambridge | ✅ | - | - |
worcester | ✅ | - | - |
dc | ✅ | - | - |
polk | ✅ | - | - |
johnson | ✅ | - | - |
chicago | ✅ | - | - |
miami | ✅ | - | - |
orlando | ✅ | - | - |
tampa | ✅ | - | - |
nashville | ✅ | - | - |
tokyo | ✅ | - | - |
denver | ✅ | - | - |
interstates | - | ✅ | ✅ |
City geofences
The geofence regions are metropolitan counties and cities across TX, CA, AZ, NV, PA, MA, IA, IL, DC, FL, CO and TN, for example travis (Austin), houston, dallas, sanantonio, sf, la, sandiego, sacramento, phoenix, vegas, philadelphia, boston, cambridge, worcester, dc, polk, johnson, chicago, miami, orlando, tampa, denver and nashville (Davidson County). Each carries its own crash and calibrated-VMT layers.
The three Massachusetts regions and chicago are municipal boundaries rather than counties, because none of those cities is coterminous with its county. The three Florida regions are the opposite case: miami is Miami-Dade County, orlando is Orange County and tampa is Hillsborough County, not the cities, because their source cannot place a crash any finer than the county. The Massachusetts regions also record no airbag deployment, so outcome=airbag and outcome=ego_airbag return a 400 there. See the note below.
Interstate corridors
interstates is not a city. It is a multi-state interstate network, and the only region that supports route and depot modes. It spans the California interstates (I-5, I-80, I-580, I-205) and the CA and AZ cross-state corridors (I-10, I-15, I-40).
For route mode you pass (route, milepost) segments, and multi-corridor trips are stitched together via a junction graph. For depot mode you pass two lat/lon pins and the engine routes between them.
California-only denominator toggle
The denominator_vmt filter (CPRD vs HPMS) is meaningful only for the California geofence regions. Every other region uses a single state-DOT calibrated denominator and rejects denominator_vmt=hpms with a 400.
Crash-year coverage is not the same everywhere
crash_year defaults to 2022, and two regions override that because of their own data.
boston defaults to 2023: 28% of its 2022 crashes were filed with an unknown severity and no injury counts, so its 2022 any-injury and serious+ rates read low.
miami, orlando and tampa default to 2023 because their source has no 2022 at all. The FLHSMV extract runs 2023-2025, so the Florida regions are the ones where asking for 2022 returns N=0 against a full denominator, which renders as a rate of 0.000 and looks like a measurement rather than an error. They are also the only regions with 2025.
Omitting crash_year gives you each region's own default, which is what the UI shows. Pass a year explicitly only when you need a specific one, and check it exists for that region: a year the region lacks is silently ignored rather than rejected.
Outcomes are not available in every region
A region whose source data cannot express an outcome rejects it with a 400 rather than returning a zero. Today that is airbag and ego_airbag for boston, cambridge, worcester, dc, polk, johnson and denver, and police_reported and ka for tokyo, whose source holds injury and fatal crashes only and has no serious-injury flag. The Florida regions record deployment on 99% of crashes at every severity, so both airbag outcomes are available there. observed_any_injury and fatal are available everywhere.