Скачать или смотреть Trail Data Issues - Bear Creek Trail (Duplicate Trail)

This video covers a new type of issue I have discovered with the COTREX trail data - duplicate trails. In particular this video looks at the Bear Creek Trail which is managed by Jefferson County Open Space Parks and Trails - although it also crosses into other jurisdictions. The issue in question is centered around 39.637447, -105.2803602

Avoiding duplicate trails is important. While they may not cause someone to get lost, they will impact any analysis someone does to to determine how well a given population is served by trails. For example, if you wanted to determine how many miles of trails a given neighborhood had access to within a 10 minute drive, having duplicate trails in your data would throw off this calculation.

Duplicate trails hould also be fairly easy to detect. One could just buffer all of the trails in COTREX by three meters (e.g.), and then one by one, subtract the buffered trails from the orginal linear features. If nothing remains of a trail ofter the subtraction, it is likely a dublicate, and should be investigated further.

The two trails in question have almost the same attribution/field values, indicating that they are likely duplicates.

COTREX app doesn’t filter these trails out of their web map.

However, the duplicate does not appear in the USGS data. Their either got a different version of the data from JeffCo, or they have a process that filters them out.