An interesting and varied route can include a mixture of green spaces, paths and pavements alongside roads. The route should avoid crossing roads as much as possible and if a crossing is necessary should use a pelican/zebra crossing if possible. Marshals may need to help walkers at busy road crossings and will need appropriate briefing on their duties. The principal task there will be to advise walkers when it is safe to cross. By law they have no powers to stop traffic. Knowing the kind of people who are likely to come will help you decide the distance.