There is a park I am mapping for Trail Kids, a youth program that also incorporates orienteering in their program. This is primarily a training map, but I still want to stick as much as possible to normal mapping convention. This park has an extensive mountain bike trail network which is not exclusive to MTBs, but states that hikers can use them, too. In mapping the trails I do though know that I should wear blinkers or bells or something when moving along these trails, and be ready to jump out of the way.... From an ISSOM point of view the normal foot trails and the mixed use trail would use the same symbol, however, I would personally feel so much more comfortable if there was a distinction on the map, so that someone reading the map can quickly see that when crossing these trails or running on them one has to be so much more alert...
The trails are single-track uni-directional for the MTBs, but I as far as I know hiking or trail-running is allowed in both directions.
Any thoughts on how I cold solve this?
you could put a underlay on the MTB trails.
create a new color than is just below the black used for the trails and the brown for contours but above things like greens and yellows in the color table.
I like 50% red (M=50% Y=50%) but whatever you like, maybe a 50% purple would be better for the color blind
create a new line symbol using that color - make the line wider than the black trail line.
use the 'fill or make border' tool to add the colored line to the MTb trails
if ever you want a map without the underlay just hide that symbol
You could also make various lines of different colors to show the different trail grades or a different color for each named trail. And you can add colored V symbols that show the riding direction.
I have seen this method in use on a map:http://4.bp.blogspot.com/-yACcc3BJihg/VP33isNF9iI/...
The legend says something like: "Bike downhill trail: Watch out when crossing, forbidden to run along the trail" or as the British would write: "Please stay off the trail." ;)