Ohio has 88 counties and several hundred law enforcement agencies filing crash reports. If you are scoping a crash-data pull — for a practice, for a marketing program, or for a research project — the first real decision is which slice of that you actually want.

Most people start with population, take the biggest counties, and find out later that volume and value are not the same thing.

County or Agency?

There are two natural ways to scope crash data, and they are not interchangeable.

By county is the natural unit for a law practice. It maps to venue, to driving distance, and to how you already think about where you work.

By agency is the natural unit for the data. Reports are filed by agencies, and a county contains many of them. Cuyahoga County alone has dozens of municipal police departments, plus the sheriff's office, plus Highway Patrol posts.

The consequence is worth sitting with: county coverage means aggregating across every agency inside it. If one department is slow to file, that county looks quieter than it is. That is a filing artifact, not fewer crashes, and it will fool you if you are comparing counties month to month.

Population Is a Starting Point, Not the Answer

Ohio crash volume broadly tracks population and traffic density. Cuyahoga, Franklin, Hamilton, Summit, Montgomery, Lucas, Butler and Stark have the most people and the busiest roads, and they produce the most reports.

But three things move the value of a county more than its raw count:

  • Can you actually serve it? Venue, driving distance, and whether you are staffed to appear there. A lead you cannot act on is overhead.
  • Who else is fishing there? The highest-volume counties are exactly where every other firm in the state is buying leads. Competition scales with volume.
  • Highway mix. A county carrying a long stretch of interstate produces serious-injury crashes out of proportion to its population — and often involving people who do not live there.

That third point is why some mid-size counties along I-70, I-71 and I-75 outperform their population rank for serious-injury volume.

The Out-of-County Problem

Crash location and victim address are two different fields, and nearly everyone conflates them on the first pass.

A crash on I-71 in Medina County can easily involve a Columbus resident, a Cleveland resident, and someone driving through from Kentucky. Scoping "Medina County" gets you that crash. It does not get you three Medina residents.

Decide which field you are actually scoping on:

  • If what matters is venue — where a case would be filed — filter on crash county.
  • If what matters is where the person lives — for mailing, for local advertising, for driving distance to your office — filter on address.

Most people do not think about this until the list is already built and looks wrong.

A Practical Way to Pick

The approach that tends to work:

  • Start with what you can serve today without changing anything about how you operate. Usually two to four counties.
  • Add the adjacent counties along the highways that feed them. Traffic patterns, not the county map, determine where your clients were driving.
  • Run it for 60 to 90 days before expanding. Volume and conversion per county are measurable. Guesses are not.
  • Expand on the numbers. After a quarter you will know which counties produce cases and which produce spreadsheet rows, and they will not be the ones you expected.

Statewide, and When It Is Worth It

Full statewide coverage across all 88 counties makes sense for a few specific situations: referral networks that place cases with other firms, practices with multiple offices, and anyone doing addressable or connected-TV advertising where reach is the entire point.

For a single-office practice it is usually more data than intake can absorb. A list nobody has time to work is a cost, not an asset, and it quietly trains your staff to ignore the list.

Start narrow and measure. Coverage is the easiest thing to expand later and the hardest thing to un-buy. Two counties you work properly beat twenty you skim.

Changing Your Mind Later

One advantage of running your own pipeline rather than buying a list: coverage is a setting, not a contract. You pick counties or agencies, you run it, and if the answer is wrong you pick different ones next month.

When coverage is something you negotiate at renewal, you tend to leave it alone even when the data says you should not.