Speed has been accepted as one of the important factors in crash severity. Simply put, higher your speed higher is the chance of a grievous injury in the event of a motor vehicle crash. In this regard, various agencies are using different measures to reduce speed (aka calm traffic) to reduce the number of fatalities. Some of the measures employed are:
- Legislation: Passing of relevant laws to ensure that motorists and vehicles adhere to safety standards. Some ongoing examples are Speed limit rules in MVAB (Motor Vehicles Amendment Bill) and Speed governors on commercial vehicles.
- Engineering: (This is the highlight of this post) Using different techniques to reduce the speed of vehicles. 'Engineering' as a traffic calming measure will be mentioned below.
- Enforcement: Using the police force to ensure that vehicles travel only below the speed limit and fining errant vehicles.
- Emergency: Treatment of crash victims to ensure no loss of life.
- Education: Teaching the community and society on the rules of the road and how to be safe on roads.
This post is a humble request to the Team-BHP community to help identify the various engineering measures that are used throughout the country to identify the best practices along with the bad (ineffective and dangerous) practices. Some examples are shown below.
Good Practice Judicious use of Flexible Poles Flexible poles used to demarcate the curved portion of an intersection
Use of flexible poles to segregate traffic, especially at intersections so that vehicles are forced to slow down and it helps to enforce lane discipline. Such flexible poles are used in and around Kolkata and have been found to be effective in reducing crashes especially at locations with curves where vehicles tend to overtake blindly resulting in a head-on crash.
Flexible poles along a curve with a gap for the intersection. Flexible poles to prevent vehicles from overtaking along a long blind curve along a built-up area. Flexible pole along a forest route to prevent blind overtaking.
Such poles also help reduce speed as vehicles do not have the luxury of using the adjacent lane for a sweeping turn.
Flexible pole used in urban areas to prevent overtaking. Flexible poles at urban intersections.
Flexible poles do have the advantage of being a relatively safe measure to enforce lane discipline. Due to the apparent reduction in lane width, the vehicles tend to slow down. Personally, I think that flexible poles are highly effective, but currently, the material quality needs improvement as the poles are easily destroyed by a limited run-overs.
Bad Practices
There is no dearth in bad practices. While it is easy to blame the PWD for all the bad practices, in many cases, it has been observed that the PWD had no role to play! Case and example are the
Plastic Bumps used all over West Bengal. These bumps are provided by the police and not PWD!!
That being said, some of the poor measures to reduce speed are:
Use of Police Barricades to slow traffic speed.
Police barricades are generally used extensively (at-least in WB) and have become permanent fixtures on the road. The intention of the barricade is to create a chicane and hence reduce the speed of vehicles. However, in reality, the barricades are generally not visible) especially at night and become a safety hazard themselves.
Further, in many cases, it is also noted that the barricades are placed at the apex of a curve, furthering the complexity of the curve and the drivers do not anticipate such hazard on the road!! Overall, this is a very poor measure for reducing the speed of traffic, nevertheless, it is deployed (by the police) mainly due to the pressure by the community.
Plastic humps (aka Bumps)
Terrible engineering measure as the bumps gets torn off the road when heavy vehicles ply over it. In West Bengal, the plastic bumps are provided by the police. PWD is completely against such practice as it destroys the roads.
Speed Breakers (Humps)
The IRC 99 (Indian Road Congress) does provide the design for humps, which, if followed, minimizes the
journey discomfort at the designated speed. However, the reality is that the majority of humps in India are back breakers more than speed breakers. This is compounded when there are no advance warning signs and no marking on the humps!
Sometimes multiple such back-breaking humps are provided!
The multiple backbreakers are provided along the Bally Bridge over the Hooghly River (Kolkata).
Other non-standard measures Image is taken from Google
Some measures like the 3D Zebra Crossing, while an innovative method, will not help in speed reduction in the long term. The drivers will zip over them once they realize that it is only a painting on the road!
If you have seen such measures (good ones preferably) which
effectively reduce the speed of the vehicle while simultaneously minimizes the journey discomfort, please do share it.
Disclaimer - The intention of this post is to create a discussion and a photo database which will help in developing speed policy guidelines to help relevant authorities (Police) in posting credible speed limits and engineers (PWD) in designing facilities for a safe and comfortable journey.