When you set your objectives, many moons ago during the planning phase, they should have been "SMART". And if they were, your job in evaluating how you have performed will be much easier, as you will know what you were trying to achieve and will have given some thought as to how to measure that success. So now's the time to pull out that plan and go through what you said you were going to do.
Knowing that you have been successful is more than just accounting for the money you spent, and even more than measuring the length of path that is available to the public, although these are obviously both important. The success of your project can also be measured in how many new people are using the path; the skills that have been developed in the community and the added opportunities for recreation and environmental education in the area.
One of the obvious things you might want to do first is to find out how many people are using your path. You can do that manually, by using a 'clicker' and counting the people going past. An alternative approach is to use an automatic counter, which will detect the number of people passing through it. You can find further information on the pros and cons of using these counters here. There's also information here on how to estimate visitor numbers to sites such as woodlands. It's worth asking your access authority whether they'd be prepared to donate or loan a people counter to help monitor path usage.
There are other things that are much harder to measure or attribute directly to your path network, but which are also important. These include the environmental, social and economic benefits that paths can bring. Perhaps there are more families that go out together, more visitors to the area, or more interest in the landscape and history of the area. These things all contribute to the impact you have had by developing and promoting your paths.
Evaluation is also an ongoing process, like the maintenance of the path network itself. By monitoring how people are using your paths you can decide whether any changes are needed to the way you manage and promote them.
Social, economic and environmental benefits
Paths for All (along with Walking-the-Talk) have created a Path Benefits Toolkit that should help your group to help you find out about the benefits that your path network has brought to your local community in social, economic and environmental terms.
SNH have also created a visitor monitoring manual, which you can access here.
When evaluating a path network some people only remember to take account of the initial financial cost of developing and maintaining paths. But paths have the potential to bring in money as well, in terms of increasing visitor spend in an area, or reduced health care bills.
SNH have also created a visitor monitoring toolkit, which you can access here.
SNH have also created a visitor monitoring toolkit, which you can access here.