Before revision: Enthusiasts may focus on a single activity related to roads, such as driving the full length of the highway system in a specific area , researching the history, planning and quirks of a particular road or national highway system.
After revision: Enthusiasts may focus on a single activity related to roads, such as driving the full length of a highway (known as 'clinching') , researching the history, planning and quirks of a particular road or national highway system.