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On the following roads, a curb is not desirable - highway without pedestrian traffic, rural highway (ease of pulling to the shoulder and not to restrict water flow to ditches), City streets designated as walking zone, usually for tourism/commercial purposes, and no vehicular traffic allowed. The street curbs, raised sidewalks are designed to impede the ...


3

The equation for highway superelevation is $$e + f = \dfrac{V^2}{gR}$$ where: $e$ is the rate of superelevation in %, $f$, the friction coefficient of the pavement, $V$, the velocity, $g$, the gravitational acceleration, $R$, the radius of the curve.


2

It depends on the type of the joint: The smooth dowel is used in an "expansion/contraction joint" to allow for free (lateral) movement due to thermal expansion/contraction of the concrete on either side of the joint. A smooth dowel has less surface for bonding, and no rib (small deformation around the bar) to restrict the movement. Sometimes ...


1

Hydroplaning - By definition, hydroplaning is when a vehicle starts sliding uncontrollably due to the tires encountering more water than the treads can displace. When driving at high speeds over wet pavement, the water begins to push the front tires off the ground slightly, creating a thin film between the tire and the road. That film, and the resulting ...


1

As you mentioned bitumen, tire rubber particles, fine dust, and oil can cause a roud to be slippery after a dry spell. But in your case it's not that. it could be a caravan of old trucks crossing the road earlier, have left a perfect mix of oil and rubber, or their load could have been constraction silty/gypsum material which has blown over the road due to ...


1

Usually roads become slippery after a first rainfall of the season because of all the dust and oil particles that have not been washed away and they are mixed with the moisture. Basically they create a slightly more sticky film (compared to rainwater) that acts as a lubricant between the road and the tire. (Any rain Harvesting system uses a First flush ...


1

Antivehicular ones. But also anti pedestrian, The goal is to keep pedestrians and people, bikers, etc off this section. Namely because if it should be in proximity to moving vehicles.


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