Hazmat
in Motion

Form 5800.1 sorts every release into four boxes: highway, air, rail, water. Highway takes more than nine filings in ten, because that is where the shipments are. Read the second column, though, and the ranking flips - when a rail load gets loose, it turns serious at over eight times the highway rate. One is a drum on a loading dock; the other is a tank car.

Bars share one scale. "Serious / 100" is serious incidents per 100 reported - rail runs 7.6 to highway's 0.9, 2020-2024 totals.

Read each mode across three ledgers and the ranking rearranges itself. Highway owns the paperwork: 92 of every 100 filings. But follow the lines right and rail - fewer than 2 filings in 100 - climbs to more than a tenth of the serious incidents and past half the dollar damage, edging out highway's own share. A drum leaks by the gallon; a tank car breaches by the ton.

The same shares, as a table

Mode	Incidents	Serious	Damage
Highway	92.5%	84.5%	48.5%
Air	6.0%	3.9%	0.1%
Rail	1.5%	11.4%	51.3%
Water	0.0%	0.2%	0.1%

The map is a freight map wearing a warning color. Releases pool where the petrochemical corridors run - Texas and the Gulf, the industrial Midwest, the port-and-turnpike Northeast - and thin out across the intermountain West. Read it honestly: this is raw count, so it tracks where hazmat moves at least as much as where it is mishandled.

Hover a state for its figures

Top states, as a table

State	Incidents	Serious
Texas	11,041	106
California	10,703	71
Illinois	8,978	59
Ohio	7,969	77
Florida	6,342	37
Pennsylvania	5,911	53

Reported incidents per state, 2020-2024 total, single-hue density ramp, darker is more. Counted straight from the PHMSA Incident State field.

The leaderboard reads like a hardware store with a chemistry aisle: paint, caustic cleaners, rubbing alcohol, battery acid. These are the workhorse chemicals of an industrial economy, and they spill at the rate they ship. The column to watch is the serious rate - the acidic corrosives further down the list turn serious two to three times as often as anything above them.

"Serious rate" = share of that commodity's incidents meeting PHMSA's serious threshold (a fatality, major injury, evacuation, closure, or large release). Counted straight from Commodity Long Name and Hazardous Class, 2020-2024 totals.

Put every top commodity on two axes at once - how often it is spilled across, how often those spills turn serious up - and the board comes out lopsided. The materials filed most often are also the most harmless: paint and isopropanol leak thousands of times and turn serious well under half a percent of the time. Even the single worst commodity here, a corrosive inorganic acid, crosses PHMSA's serious threshold only 1.7% of the time. There is no rare-but-ferocious corner; road hazmat is overwhelmingly minor spills, and what danger there is tilts toward corrosives and flammables.

On these roads, hazmat means trucks. Every top commodity moves overwhelmingly by highway - never under about six loads in seven - so the bars barely differ. The only visible exceptions are a sliver of air freight (small parcels of paint and alcohols) and a little rail; nothing here rides mostly on anything but the road.

The full mix, as a table

Commodity	Highway	Rail	Air	Water
Wet batteries	99%	0%	1%	0%
Isopropanol	98%	0%	2%	0%
Corrosive base	97%	0%	3%	0%
Sodium hydroxide	97%	1%	2%	0%
Hydrochloric acid	95%	2%	3%	0%
Ethanol	95%	0%	4%	0%
Flammable liquids	94%	2%	5%	0%
Paint	93%	0%	7%	0%
Alcohols, n.o.s.	86%	6%	7%	0%

Filings are up roughly 27% across five years - more freight, wider reporting, and a battery in every parcel. The serious count refuses to follow. It holds near a constant floor through the whole climb, which means almost all of the growth is minor spills that now make it onto a form. The paperwork is exploding; the catastrophe is not.

Spills follow the freight calendar and the thermometer. Reports climb through spring, peak in July - heat swells drums, softens seals, and raises vapor pressure in every tank - and ease off into winter. The serious count, once again, barely notices: catastrophe keeps its own schedule.

Nearly half the file doesn't say why in words this bucketing can parse - "Other or not reported" leads by a wide margin. Of what can be classified, the register of failure is mundane: a cap not torqued, a fitting worked loose, a drum abraded or punctured in transit account for nearly all the rest. The vehicle accident, the image everyone carries, is barely on the board - a single coded report - and it is the one that turned serious.

This is the dek's promise made literal. Start with every form filed over 2020-2024 and follow the consequence down. Almost all of them - 19 in 20 - involve an actual release, not just paperwork. From there the drop turns severe: barely 1 release in 455 finds an ignition source. Fires are dangerous once they start - most of them hurt someone - but very few of those injuries end in death. The catastrophe is real. It is also 1 filing in roughly 10,200.

Bar length is on a base-10 log scale so each tier stays visible; the counts are the honest measure, 2020-2024 totals.

Compare tool Put two materials side by side Mode mix, serious rate, and volume for any two of the top commodities - shared scales, no invented numbers. ->