Background Image of a River

Topic | Mapbox

City of Lancaster Public Transit

A NodeJS GTFS Feed & Interactive Map Generator

This project consists of a NodeJS script that generates a GTFS feed and interactive map. The only requirements are a GeoJSON routes file, a GeoJSON and stops file, and a handful of static GTFS text files. The result is a feed that can be published to Google, Transit, or any transit feed service, as well as an interactive map with schedules for each route. The schedules can be fixed route with specific times or loop routes that run every hour.

Peaks 3D Visualization

An Exporation of the Highest Mountain Peaks in the US

An exploration of the Mapbox GL JS 3D terrain functions, using the tallest US mountain peaks in each state as the study subject. Each map view in this demo project was carefully selected to provide an excellent view of the peak and its surroundings. The terrain extrusion still has a tendency to crash browsers.

Wedding Website

A Single-Page Wedding Wedsite with an Interactive Map

This single-page website features image modals, an interactive map and a contact form. The website is bundled with the Parcel bundler and hosted with Netlify which also takes care of form reponses.

Pandemix Data Visualization

What if all US COVID Deaths occurred in one geographic area?

This project is based on the amazing map Brazilian Lupa. It uses a dot density visualization to represent deaths from US COVID-19 clustered in one geographic area. The populations are based on US Census Block Groups, with one dot representing 20 US deaths. All statistics are generated client-side using vector tiles and web-workers

From the Ashes of Shapefiles

A Presentation for the 2020 Virtual Ohio GIS Conference

This talk describes the slow and painful migration from a legacy GIS data structure of hundreds of shapefiles to a modern setup using a mix of Postgres, QGIS and ArcPro. Many small organizations and municipalities face this issue and it is one that is sure to resonate even with those supporting a...

GIS and Remote Work

An Exploration of a GIS Remote Work Toolkit

In the aftermath of the Coronavirus pandemic, remote work may well be come the new normal, as businesses and government agencies discover that productivity can be maintained or even increased when implementing remote work options. And the tools to implement this transition at the employee level a...

Ohio COVID-19 Dashboard

A Simple, Client Side Tracking Dashboard for COVID-19 in Ohio

Update: This visualization is no longer being updated. There are a wide variety of authoritative COVID-19 trackers on the internet, including ones from Bing, Google, National Geographic, the New York Times, as well as the sites listed at the bottom of this post. Please refer to these for the ...

RTK to WGS84

Transforming Coordinates with JavaScript using proj4.js

In my day job we recently completed a project to field locate our water utility assets using a high-accuracy GPS unit. Now that this data is online and accessible in our web maps, our field crews requested a method to locate these assets again using GPS if need be, for instance if there is a foot...

Highlighting Features in Mapbox GL JS

A Comparison of Filter and Feature-State

Creating a hover effect is a great way to add interactivity to web maps. In mapbox-gl there are two main methods to accomplish this feature: setFeatureState() and setFilter(). Up until now (late 2019) I had been using the setFilter method to create a highlig...

Network Tracing with Turf JS

A Client Side Solution for Simple Upstream and Downstream Linear Network Analysis

A primary focus of my day job is managing utility datasets for a small municipality. I am currently in the process of taking a simple database of lines and points and turning it into a true utility network. One of the benefits of having this new seamless database is to perform network traces. Thi...

Progressive Web Apps

Using PWA Components for Web Maps

The GitHub repository with all the code needed to follow along with this presentation can be found at The live demo is available at

Leaflet Store Locator

A Leaflet Version of the Original Mapbox JS Store Locator Example

This simple, responsive store locator is based on the original Mapbox JS example, tweaked to use Leaflet 1.0 and custom icons. The sidebar uses a jQuery filter function (thanks jsfiddle). The nearest store function uses TurfJS, b...

Intro to Turf JS

Geospatial Analysis for the Browser, Desktop & Server

This presentation was given at the 2018 Ohio GIS Conference. The NodeJS example is hard-coded from a real-world example in the original presentation and has been replaced with the estimated response time....

Mapping with Vector Tiles

Query Features Outside the Viewport

The goal of my original post on client-side web mapping for large datasets was to create an inexpensive, robust county-wide parcel viewer web application. The base functionality would include the ability to both identify and sear...

GPX Visualize

A Visualization for GPS Tracks

This pojects uses the medium of GPS tracks to explore the linking of charts and maps. The application has a dark and light theme with custom map styles for each. The display can be exported to a an image by clicking in the upper right corner of the visualization.

Data-Driven Styling, 3D Polygons & Vector Tiles with Mapbox GL JS


Web Maps from Scratch

An Introduction to Leaflet, GitHub & Jekyll


What is a Map?

Marshall Univerity 2016 GIS Day Keynote