摘要 |
<p>A reactive speed hump (2) includes a fluid flow control valve assembly (4). A first valve (18, 20, 21) is naturally open and a second valve (10, 14, 15, 16, 17), naturally closed. Application of fluid pressure on the control valve assembly below a first lower threshold level or above a second higher threshold level allows a flow of fluid from the inlet to the outlet, but an application of fluid pressure on the control valve between said first and second threshold levels allows substantially no fluid to flow between the inlet (7) and the outlet (9).</p> |