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During my recent visit to Kruger, I noticed again that in several places, sections of tarred road have been deliberately covered by a thick layer of sand. What is the purpose of this ? To hide the tar as sand is more aesthetically pleasing ? I'd be interested to know.

Sand is deliberately spread on the tar roads to make the tar last longer. As the tar heats up, the sand penetrates it and binds the tar strongly together again. This is done on a regular basis on all tar roads in Kruger

It is done with a big grader type machine that spreads the sand on the road as it drives along.

If they put sand on the tar to bind it when it heats up, then why don't they do this on roads outside the Park ? I have never seen this being done outside the Park. Is the tar in the Park of a lower quality than outside the Park - perhaps due to the lower speeds ? Surely someone from Kruger can answer this for us ?

Dear Camponotus
The tar is resealed regularly during the summer months with a layer of tar that is spread on the surface of the planned sections of tar roads in Kruger National Park. After the tar has been sprayed on the road, a layer of sand is spread on the new layer of tar to bind with the tar and to reseal the road properly. For this to be effective, the road temperature must be high enough. This is why you'll always see this kind of maintenance on our tar roads during the hotter summer months. The sand also helps to prevent damage to our guests' vehicles while the new layer of tar is still wet. We try not to close roads during this maintenance neither will you see any detours during this operation. If detours must be provided, it will impact heavily on the environment next to the existing road and we can't let that happen. This is a very short explanation of the process. If you need more detailed information, I'll get it for you from our roads expert in Kruger National Park.

Plenty of sand on the tar at some places.

Here is aview of it near Skukuza going towards Kruger Gate.

Yeah, the sand is basically used to bind the newly tar road better and make it stronger.

And to avoid it crumbeling on the sides and breaking out pieces .. Drove the Phalaborwa road when they chucked sand on .. they should do it more on that road .. the sand has an additional function .. reduce speed of vehicles.

Hi MikeV

This is one of those issues where I agree with our Technical Services and this sand is the correct way to go here. On roads outside the KNP, they normally spread stones on the tar which has more or less the same effect but acts quicker and can handle faster speeds. With the slower speeds used in Kruger, you can actually use sand which over time, binds stronger than stone (more compact) and creates a safer and longer lasting road surface.

Often roads teams outside the park open the roads a little too earlier and the tar-and-stone combination makes an awful mess on vehicles. Personally, I would rather have the sand than the tar-and-stone combination, wouldn't you?

The other alternative is to close the road completely, build environmentally damaging detours or divert traffic on other routes. Not really feasible in my opinion.

Thanks DB for finding Kruger's old post to explain this.

Kind regards
KNP Spokesman

Agree , the sand over tarspray is perfect . Just watch your car if you don't have mudflaps .

If only for the accomodation and tar roads the KNP is the greatest reserve in Africa . The road network is what makes KNP accesable and convenient to the tourist and as such is an asset unequaled in Africa .

David Paynter , in his book of 1985 "Kruger , an African ...." also described the process of road building bearing out what has been said .
But he did also say that the road needs to be redone regularly ( say every 5 years ) to keep it sealed , prevent cracks and potholes , and prevent water ingress which will destroy sub-base layers . Also there was the issue of teams having to remove dung which sticks to the road and is inclined to deteriorate the surface , both chemically and physically .
I trust that this is still being done , and that cost cutting (as in the rest of the country) on infrastructure is not being applied to make the annual statements look good .

IMHO the gravel roads have been neglected for too long and will probably have to be ripped , regravelled and graded , a major expense . The vegetation on the side will also have to be graded back and the runoffs recut . The Orpen dam road is the perfect example .

sand being laid between Kruger Gate and Skukuza

If I am correct, they cover tar by sand to protect the tar from the heat, aswell as erosion, so the effect of the weather (heat) and erosion is reduced..

Monné

Dablims - it is part of the road maintenance - they spray an asphalt mulch on the road to seal it and then cover with a fine sand layer - some of this sand sticks to the "tar" and becomes a new layer. The rest is blown away over time. So the more you drive over it you help resurface the road

Billy, although that is true in general, I don't think this is the particular case with the Olifants road. Laine and I discussed this very same thing whilst driving up there a couple of weeks ago. She's been to Kruger far more than I have and she said that she can recall seeing sand there almost on every trip she's gone that way. I too can recall seeing sand here very often.

Was it washed up there? Blown perhaps? I don't know, but to me this is not part of SANP's road maintenance work.

I also assumed it's part of the road maintenance..........we've seen the sand on that road December 2010 and again January 2012.

In July 2011 they were busy doing the same on the road north of Afsaal up to the T-junction.