GIS Mapping for Site Selection: Understanding What the Location Actually Tells You

GIS mapping helps companies evaluate locations by connecting business requirements to geography. It brings workforce, transportation, demographics, infrastructure, hazards, and other factors into a spatial view so a team can understand how they relate to a potential location.

That sounds straightforward. The interesting part starts when you look beyond the headline numbers.

A market might have the population you want, but where do those people live relative to the site? A region might have a strong manufacturing workforce, but does its occupational mix fit the operation you’re planning? An available property might look convenient on a national map, but what happens when you account for the road network, access points, and surrounding development?

Those are different questions, and they deserve more than a pin on a map.

I’m a geographer by training. Around Vista, I also answer to Map Daddy, Don Memo, and Zig. Somewhere along the way, that produced Zig’s Law of Maps: “Every spreadsheet secretly wants to be a map. Your job is to set it free.”

There is a little office humor in that. There is also a reason I keep coming back to it. Once information has a location, you can start seeing relationships that are difficult to recognize in rows and columns.

What GIS adds to a site selection decision

A spreadsheet is useful for comparing markets. I work with plenty of them. But a regional total doesn’t tell you how that region works on the ground.

Two properties in the same county can have very different access to workers, customers, highways, and infrastructure. A river crossing or a limited number of interchanges can change the practical reach of a location. So can where people live within a growing metro.

GIS gives us a way to investigate those differences.

We can start broadly, looking across markets for patterns that fit a business, then narrow the analysis as the requirements become more specific. At the property level, we can examine the surrounding geography and identify questions that need further investigation.

The value comes from connecting those scales. A strong market doesn’t make every site within it a strong choice, and a promising property still needs a market that can support the operation.

Start with the business question

Before choosing layers or building a heat map, I want to understand what we’re trying to learn.

A manufacturer recruiting a particular mix of production and technical occupations needs a different analysis from a retailer studying customers. A distribution operation has different transportation requirements from an office evaluating employee relocation.

That affects which datasets belong in the analysis, which geography makes sense, and what the finished map should communicate.

Common inputs include:

Input	What we’re investigating
Workforce and occupations	The size, composition, cost, and distribution of relevant labor
Population and demographics	Who lives in an area and how that population is changing
Transportation	Access to workers, customers, suppliers, and transportation facilities
Utilities	Service areas, infrastructure, and requirements to verify with providers
Property and land use	Parcel boundaries, surrounding uses, and mapped development constraints
Natural hazards	Potential exposure that requires closer investigation
Incentive boundaries	Whether a location falls within a relevant program area

A mapped utility line doesn’t establish available capacity. A population count doesn’t establish how many people you can hire. An incentive boundary doesn’t establish that a project qualifies.

The map helps us identify where to investigate and what to ask next. The underlying information still needs to be understood and, where appropriate, confirmed.

Getting deeper than county averages

I like to get as deep into the geography as the question and the available data reasonably allow.

County-level information has a place. It can be useful for understanding broad patterns and making regional comparisons. But counties vary enormously, and an average can hide the differences that matter to a particular site.

Depending on the analysis, we may work with census tracts, block groups, parcels, hexagonal grids, or drive-time areas to get a more useful view.

Hex grids help standardize the geographic framework so we can make more consistent comparisons and reduce distortions associated with irregular administrative boundaries. The goal is to get a more accurate picture of the geography and reveal patterns that county or ZIP code averages can hide.

That framework still needs appropriate data behind it. Putting a state-level value into thousands of hexagons doesn’t turn it into thousands of local observations. Interpolating between regional values produces a modeled surface. Both can be useful, provided the map explains what the reader is seeing.

That distinction matters to me. I want a map to reward a closer look, and the information behind it needs to hold up when someone takes one.

Drive times depend on the question

A radius is a useful starting reference, but roads rarely cooperate with a perfect circle.

Drive-time areas, also called isochrones, estimate the places reachable within a specified travel time through a road network. They help us examine labor access, customer reach, and other relationships where distance alone doesn’t tell the whole story.

The right routing approach depends on the question and the data available for that analysis.

For some screening work, I like looking at an off-peak scenario, often around 3 a.m., to understand reach under lighter traffic conditions. That gives us a view of what the network can connect when congestion is less of a factor.

I also know that it can expand the area and the population within it, so it needs to be labeled accordingly.

If we’re investigating the commute to a facility, we can examine relevant arrival times, departure times, and shift patterns. An 8 a.m. scenario may answer a different question from an overnight shift. Travel toward a site can also differ from travel away from it.

The point is to choose assumptions deliberately and make them visible. A “30-minute drive time” is much more useful when everyone understands which 30 minutes we mean.

And once we draw that boundary, we still need to examine who is inside it. Total population is a starting point, not a staffing plan.

How I turn research into a map

When my coworker Janie Hanna was developing an article about aerospace and defense, I read the narrative and went looking for the data that could help readers understand the geography behind it.

I pulled information from the Bureau of Labor Statistics, the Census Bureau, and other relevant sources, brought it together, and explored what it actually showed. That work became five maps published alongside her Area Development article, covering aerospace employment, established and emerging markets, workforce depth, wages, and industrial electricity prices.

The article provided the context. The research helped determine what the maps could responsibly say.

That is an important part of my process. I want to spend time with the information, explore the relationships, and understand the story before deciding how to explain it to someone else.

You can see the finished work in How Aerospace and Defense Site Selection Criteria Are Evolving.

Good cartography takes care

I love taking complicated information and creating something that makes someone stop and say, “That’s cool. Look at the detail.”

I care about that reaction because it gets people looking. Then the map needs to give them something worth understanding.

The colors, labels, scale, hierarchy, and supporting notes all contribute to how someone reads the information. A poorly chosen classification can exaggerate a difference. An overloaded map can bury the useful finding. A beautiful map can still be misleading.

I take pride in the finished work, and that includes the analytical choices as much as the visual ones.

Sometimes a detailed exploratory map helps me understand the subject. The version I present may need a much clearer focus. Other times, several related maps tell the story better than one map trying to carry everything.

The work is figuring out what the audience needs to see and giving it enough context to make sense.

Questions to ask before trusting a site selection map

Before using a map to support a location decision, I would ask:

• What does the underlying data measure? Residents, jobs, employed workers, and potential recruits are different things.
• How current is it? A publication date and the period represented by the data may differ.
• Does the geography fit the question? A regional average may be useful for screening but inadequate for comparing neighboring properties.
• What has been modeled? Estimates, interpolation, and scoring assumptions should be identifiable.
• Are comparisons consistent? Maps using different scales or classifications can create misleading impressions.
• What travel assumptions apply? Time, direction, mode, and traffic conditions affect accessibility.
• What still requires confirmation? Utility capacity, property conditions, program eligibility, and other requirements may need direct verification.
• Can the reader find the sources? The map should make its evidence and limitations understandable.

A map should help someone ask better questions. It should also make clear which questions it hasn’t answered.

Choosing a site selection mapping tool

You don’t need an enterprise GIS license to begin exploring location questions. Public resources such as Census OnTheMap and FEMA’s flood mapping tools can provide useful starting information.

Vista’s free platform, The System, offers access to more than 1,400 demographic variables and 2.9 million H3 hex cells across the United States. Users can explore mapped information, and its GridIQ tool can use a plain-language business description to suggest variables and weights for a starting heat map.

That makes it easier to begin investigating a question. The next step is understanding whether those inputs and assumptions fit the business.

For a specific location decision, custom analysis may involve additional datasets, a tailored staffing profile, different travel scenarios, or a comparison built around the operation’s requirements.

The software matters. So does the judgment behind how it is used.

Frequently asked questions

What is site selection mapping?

Site selection mapping uses geographic information systems to investigate the factors affecting a location decision. It helps teams examine where workforce, transportation, customers, infrastructure, and constraints overlap or conflict.

How is GIS used in site selection?

GIS can support regional screening, market comparisons, drive-time analysis, labor access assessments, and property-level investigation. It also helps communicate findings so people from different parts of a business can evaluate the same geography.

Why look below the county level?

A county total can hide substantial differences within its boundaries. More detailed geography can help assess a particular location, provided the source data supports that level of analysis.

Why use hex grids in site selection?

Counties and ZIP codes vary widely in size and shape, which can distort comparisons and hide local patterns. Hex grids give us a more consistent geographic framework, helping reduce those boundary effects and compare locations on a more comparable basis. The goal is a more accurate picture of the geography, supported by appropriate data and methods.

Does a drive-time map show the available workforce?

It shows an estimated area of accessibility under specified assumptions. Assessing workforce requires examining relevant occupations, wages, competition, hiring requirements, and other factors within that area.

What is the best site selection mapping tool?

It depends on the question. Public tools and platforms such as The System can support exploration. A project-specific decision may require custom analysis and confirmation beyond what a public map provides.

Bring the question and the spreadsheet

What I enjoy about this work is taking a complicated question, digging into the information, and finding a way to make the geography understandable.

Sometimes that reinforces an initial idea. Sometimes it opens up a different way of looking at the problem. Either way, the goal is to give the people making the decision a clearer understanding of the location and what still needs investigation.

If your team is evaluating markets or sites, Vista’s site selection consulting team can help connect the research to the decision.

And yes, bring the spreadsheet. You know how I feel about those.

Sources and related reading

• The Map Daddy of Site Selection and Zig’s Law of Maps
• The System: platform specifications and capabilities
• Area Development: How Aerospace and Defense Site Selection Criteria Are Evolving
• H3 documentation
• UCGIS: Problems of Scale and Zoning
• U.S. Census Bureau: LEHD applications and OnTheMap
• FEMA: National Flood Hazard Layer