In Dakar, paving streets with many hands and few machines
In Dakar, paving streets with many hands and few machines
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DAKAR, Senegal — A small crew of young men and women are fast at work in the Place de l’Obélisque, turning the central square of this capital city from a wide patch of asphalt and sand sidewalks into a colorfully paved plaza.
The paving program won’t solve all of Dakar’s road problems. There’s not sufficient funding to repave the whole city and even if there was, it would take 20 years to pave all the streets at the current pace.
But the paving is solving some of Dakar’s problems. The pavers are designed to facilitate rainwater drainage. Small spaces between the blocks allow water to filter into the ground rather than run off. In a neighborhood called Grand Yoff, which has suffered from constant flooding during the rainy season since the mid-1990s, streets now drain better as a result of the paving program. Sand streets and sidewalks that used to wash out in heavy rains are now stabilized.
And one thing everyone agrees on is that the newly paved streets look great. The colorful geometric patterns are giving parts of Dakar a distinctive look. On roads where pedestrians previously had no choice but to walk in traffic, there are new paved walkways where adults stroll or sit talking under trees while boys and girls play. “The dream has become a tangible reality,” says Theophile Bama, director of Yelhy Technology Africa. “There is a qualitative change in the appearance of Dakar.”
London to trial “intelligent” pedestrian crossings
London to trial “intelligent” pedestrian crossings – Time allowed changes with number of people waiting to cross.
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Ever walk halfway across a road only to have the light change and force you to make an undignified rush to the other side? The answer is almost certainly yes. If you’re in London, that may soon be a thing of the past however, with Transport for London (TfL) announcing upcoming trials of an “intelligent” pedestrian crossing. Called the Pedestrian Split Cycle Offset Optimisation Technique (SCOOT), it’s part of a £2 billion to £4 billion (US$3.3 billion to US$6.6 billion) program to improve roads over the next ten years and decrease traffic fatalities in the capital by 40 percent by the year 2020.
SCOOT addresses the problem of how to properly time pedestrian crossings in such a way as to make sure as many people as possible cross with the lights, as well as keeping traffic flowing as smoothly as possible. This is especially difficult in high traffic areas. Ideally, the light should be timed to allow everyone to cross, but pedestrian traffic isn’t uniform and what might work for two people might not work for a dozen. Worse, there’s the problem of pedestrians pressing the request button and then crossing against the lights or simply walking away, which creates needless delays.
Pedestrian SCOOT seeks to remedy this by using video cameras to count the number of people in a digital “box” on the crossing pavement. If a large number of people are detected, the system alters the timing of the green walk light to allow more people to cross safely. In addition, if no one is at the crossing, or if someone presses the request button and then crosses against the lights or walks away, the system switches to “call cancel” and doesn’t activate the walk light.
Starpath spray-on coating lights your way without electricity
Starpath spray-on coating lights your way
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UK company Pro-Teq is trial-testing a glow-in-the-dark spray applied elastomeric coating that could prove a cheaper alternative to conventional street lighting.
We’re used to seeing solar-harvesting technology being installed primarily on rooftops, but other sufficiently irradiated surfaces, including sidewalks, are also being explored for their energy harvesting potential.
Starpath doesn’t produce electricity, but it does offer a possible alternative to street lighting, with very low installation and maintenance costs, as it can be just sprayed onto an existing surface and then further coated to make it waterproof. According to the company, the coating absorbs and stores UV light during the day and releases it at night, when its particles are able to adjust to the available natural light, and glow with the appropriate level of intensity
GoProGreen.com 