Pink concrete edges give visual warning on low water crossing over Cherry Creek at Holly Street bridge, Denver; photo by Stuart Macdonald, 14 Oct 09
Regarding the current Trail Accessibility Guidelines in place under the US ABA, they would generally meet those requirements, as long as they are well maintained and surfaces are kept firm and stable (i.e. sand and pebbles are removed after floods). Also, obviously, during flood periods, the trail would be closed and therefore inaccessible.
Functionally, these types of crossings can be much more accessible because gradual grades can be maintained. These crossings do not need to rise up above the 100-year mark (as bridges generally do), making it easier in areas with little topography to meet the grade requirements for accessibility. The greatest accessibility issue I see is in providing edge protection to users. This is not required under our ABA Trail Accessibility Guidelines, but if they make sense for safety, any raised edge protection or railings simply don't work. The best that most trails do is provide color and texture differentiation at the edges in order to make them as safe as possible for folks with visual impairments.
Trail crosses stream in open space park on side trail along Four Mile Run in Arlington, Virginia
Low water crossing on side trail along Four Mile Run in Arlington, Virginia
Concrete structure carries trail over a small stream at Bible Park in Denver, Colorado
Concrete structure carries trail over a small stream at Bible Park in Denver, Colorado
Cherry Creek Trail in Denver, Colorado is crossed by both a steel trail bridge and low-water concrete trail structure
Waller Creek Trail in Austin, Texas crosses the stream underneath a street bridge
Cherry Creek Trail in Denver, Colorado is crossed by both a steel trail bridge and low-water concrete trail structure
Built in 2006, the Janet Fish Pedestrian Bridge honors the founder of the Shoal Creek Hike and Bike Trail in Austin, Texas
Janet Fish Pedestrian Bridge in Austin, Texas
Low water crossing before trail enters road culvert on the Clear Creek Trail in Wheat Ridge, Colorado
Low bridge over tributary to Cherry Creek built in 2009 at Monaco Street in Denver, Colorado
Low water crossing over Cherry Creek at Broadway Street bridge in Denver, Colorado
Pink concrete edges give visual warning on low water crossing over Cherry Creek at Holly Street bridge in Denver, Colorado
Low water crossing built in 2009 on Cherry Creek Trail in Denver, Colorado
