Understanding speed bumps (II)

It is placed across the road to slow traffic and are often installed in a series of several humps in order to prevent cars from speeding before and after the hump; Their shapes are parabolic (rising and falling curve), circular, and sinusoidal (oval);12 to 14 feet (3.7 to 4.25 m) in length, and spans the […]

It is placed across the road to slow traffic and are often installed in a series of several humps in order to prevent cars from speeding before and after the hump; Their shapes are parabolic (rising and falling curve), circular, and sinusoidal (oval);12 to 14 feet (3.7 to 4.25 m) in length, and spans the width of the road with height ranges from 3 to 4 inches (7.5 to 10 cm);shorter lengths and greater heights of installed speed humps slow cars greatly. However when placed in a series of 350-550 feet (100-170 m) apart, humps  reduces speeds by 8-10 mph (13-15 km/h) with warning sign notifying motorists before humps; Pavement markings also enhance visibility and a taper edge near the curb to allow a gap for drainage. Speed humps are used in locations where very low speeds are desired and reasonable and are typically placed on residential roads and are not used on major roads, bus routes, or primary emergency response routes. Placement is generally mid-block between intersections. Speed humps slow cars to 16-32 km/h. The relatively long slopes of speed humps gradually accelerate the entire vehicle in vertical direction, causing the perturbation of the cab to become progressively more severe at higher speeds; typical speeds resulting from speed humps are 15-30 km/h. Studies show an average 18% reduction in traffic volume and an average 13% reduction in collisions when installed.
Speed cushions are another type and  are designed as several small speed humps installed across the width of the road with spaces between them; installed in a series across a roadway resembling a split speed hump. The cushions forces cars to slow down as they ride with one or both wheels on the humps. However, the wider axle of fire engines (and other large vehicles) allows them to straddle the cushions without slowing down. Unlike speed cushions,  speed table (or flat top hump) is a long speed hump with a flat section in the middle; length enables the entire wheel base of a passenger car to rest on top. The long, flat design allows cars to pass without slowing as significantly as with speed humps or cushions. Because they slow cars less than similar devices, speed tables are often used on roads with typical residential speed limits and can also be designed as pedestrian crossings.Often,a 40 – 45% decrease in accidents per year with the use of speed tables is achievable in many locations where the tables are installed. It is effective in calming traffic on streets where the speed limit needs to be maintained rather than slowing cars more significantly. Traffic speed, volumes, and accidents have been shown to decrease with the use of tables
  Speed bumps are necessary on our roads. However, speed limiting infrastructures are necessary and will only be implemented or sustained often after due road safety audits and necessary guidelines and not because of perceived indiscriminate needs or requests by the public; It complements other speed management measures since most of our motorized public has a driving culture of excess or inappropriate and unsafe speed limits on various segments of our roads, particularly for built up areas with 50km/h maximum limits. Speed bumps reduces road traffic crashes as passengers in a vehicle involved in a crash whose impact speed is about 80km/h are 20 times likely to be killed than if the impact speed was 32km/reduces road traffic crashes and severity as a vehicle that hits a pedestrian at as low a speed of 15km/h can result into fatality. Generally speed bump increases safety on residential streets, and single interstate carriageways that pass through villages and towns. It improves the environmental quality of residential neighbourhoods and improves traffic flow in residential areas; reduce speed in industrial areas with heavy truck traffic where high speeds can lead to roll over; slows down traffic on public roads where there are schools, hospitals, markets and other places like railway level crossings and tollgate areas around expressways
 Yet, there have been criticisms on the management of speed bumps. While some are indeed genuine, others are based on lack of proper education. Despite these criticisms, the point must be made that wherever speed bumps are installed with all necessary standards and procedures followed, it is the responsibilities of the motoring public to comply. It is also instructive to note that specific types of bumps are used for different locations on roads that require them and must be done to specifications as approved and supervised by the appropriate authorities who must ensure that adequate  signages  such as warning signs  are put in place ahead of the bumps. The cost benefit of crash reduction outweighs the negligible issues of increase in traffic noise from braking and acceleration of vehicles on streets with speed humps, particularly from buses and trucks, increased vehicle fuel consumption and emissions, discomfort for drivers and passengers, as well as increased wear and tear on brakes, engine and suspension components. Should motorists drive over these devices slowly it would not aggravate persons with spinal troubles or chronic backache.