credit: Flickr user Roy Luck
Vertical elements like bollards, concrete domes, or plastic “armadillos” provide visual and physical lane delineation.
Bollards should be 30–42 inches in height to achieve full visibility.
Many types of bollards are available in a range of costs and designs, and can be integrated into the streetscape.
Assess design speeds, urban design guidance, and contextual characteristics to determine bollard design and style. Fixed bollards must be adequately anchored to absorb forces from vehicle impacts.
Bollards must be readily visible and include either retroreflective surface or lighting elements.
Bollards may be applied for full block segments or at specific locations where warning is desired.
LOW VERTICAL ELEMENTS
credit: Houston Metro
Low concrete domes can be applied to existing streets and provide both a visual and tactile cue to drivers to prevent incursion.
Plastic “armadillo”-shaped elements are an easy-to-install alternative.
Markings should be used to clearly delineate the presence of raised domes.
Planting strips enhance the streetscape while providing vertical and horizontal separation. Plantings require additional space and maintenance. Xeriscaping may provide an attractive low-maintenance alternative.
Plants must not block sightlines or impede the running way. Maintain some clearance between plantings and travel lanes or transitways where possible, or use plants that grow vertically without trailing. Shrubs require regular trimming and may not be desirable where clear sightlines are required. However, trees and shrubs are often suitable on fully separated transitways.
Trees that drop leaves, particularly all at once in the fall, can create slippery conditions for both bus and rail vehicles.
Avoid plantings that might grow to encroach on intersections to ensure pedestrian access and safe interactions with vehicles.
Bioswales and connected planters assist with stormwater management (refer to the Urban Street Design Guide).