The maps on these pages are all generated from vector data, from multiple sources. The main infomation contained on the maps are:

• State boundaries (green)
• Major lakes/rivers (blue)
• Major roads (grey)
• GPS tracks from driving (red)

The GPS data is recorded by my car, and it could have gaps from lack of coverage, software crashes, or if the computer isn't actually turned on. It takes a sample of the current position four times a minute. Altitude data is logged, but I found it to be very unreliable, with variations of hundreds of feet, even when stationary. I think this is a problem with the cheap GPS receiver in the car, the Garmin hand held receiver tends to be more accurate.

The maps that are generated for each day only include the driving done on that day, but they are zoomed in for greater detail.