J . Median Slow Down
Center medians or islands that narrow a road are often landscaped to provide a visual and physical amenity . Center medians or islands are placed at entrances into neighborhoods or at a mid block crossing , combined with textured pavement and landscape improvements , to help slow down traffic and create a gateway for the neighborhood ( Figures 7.9.29 and 7.9.30 ).
Figure 7.11.30 . Example of mid block median slow down through neighborhood street .
Legend W - Travel lane width = 14 ’ -0 ”
WL - Width of slow point / median ( varies depending on street width , 12 ’ minimum )
L - Length of slow point , varies depending on parking and driveways
D - Horizontal deflection , 6 ’ minimum
T - Transition , calculated as follows : T = ( D x S < 2 ) / 120 - minimum Where : D = deflection in feet S = 85th percentile speed in mph
Note : Median landscape planting should not obscure driver ’ s view . Refer to City of Arlington ’ s Design Criteria Manual for clear zone requirements .
Figure 7.11.29 . Site plan of mid block median slow down traffic calming device .
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