[pgsagar]

[quote=tsk1979;68938]Dont do that dude!!, at high speeds tire pressure should always be 2-4psi above the recommended. The recommended is he minimum, not the max.

I am not sure if I am right, but I was under the impression that tyres' pressure increases as the tyres heat up and air inside it expands, when driven on hot surface roads at high speeds. This heated air would increase the tyre pressure by at least 4-6 psi. Shouldn't then one keep the pressure lower before commencing on a long highway drive?

The Expressway is wide, 6-lane and cordoned off almost all through its length, but the surface is not very good. One, it's very uneven and rough and two, it's concrete. Concrete highways are notorious for chewing up tyres. If a tyre lasts for 35,000 kms on an asphalt road, then same would probably wear out completely at 25 to 30,000 kms. Also what a racket the tyres make on concrete! Very scary and distracting.

I am also against imposing speed limit for cars on Expressways. But motorists should be wise enough to stick to a self-imposed speed limit for their own safety. This self-imposed speed limit should take into account the size, type and condition of car, skills of driver and mental and physical state of driver, the load, the time of the day ( or night ), adjoining vehicular traffic and their distance from and weather / wind condition. A rickety jalopy of battered truck at 100 kph would be far more unsafe than a brand new Accord doing 150 in the hands of a good sober driver.

[itwasntme]

Some of the reasons could be:

1. Sheer excessive stupid speed: As other TBHP-ians have pointed out, many drivers simply floor the pedal as soon as they hit the Expressway regardless of maintaining a 'safe' cruising speed; Different cars have different 'safe' speeds with a sensible cap of say 120 km/hr.

2. Inexperience of handling their own vehicles > 100 km/hr: This is probably a prime cause of accidents with many drivers simply not aware of the pitfalls of driving at speed in their own cars! Crucial factors like reduced reaction time, sensitive steering feel when at speed, significantly increased braking distances and 'tramlining' are totally forgotten during the 'pedal-to-the-metal' driving. As a result, people treat a 120 km/hr drive like a 80 km/hr with potentially fatal consequences.

3. Under-tyred cars and/or with worn/balding/damaged/unmatched tyres: Take a Swift LXI/LD/VXI/VDI for example. The stock tyres are totally inadequate for the comparatively heavy Swift body. Drive it at maximum speed to-and-fro on the Expressway on a hot afternoon and an accident caused due to oversteer/understeer or a catastrophic blowout is almost guaranteed. I have seen Expressway cars with tyres which I would not put on my kid's tricycle! One of my standing pre-Expressway tasks was to rigorously inspect all 4 tyres (and the spare) for damage (bulges/cracks/bald spots etc) by rolling the car to-and-fro / getting down on my knees / taking out all the stones etc from the treads. This simple exercise could make the difference between a simple sidewall bulge and a cracked skull!

4. Road debris & rough surface: I am quite sure that debris on the road is another prime cause of catastrophic accidents on the Expressway. The concrete surface conceals small stones/sand etc much better than a 'blacktop' with the result that a driver already max'ing his vehicle will not be able to spot and avoid in time. Also the comparatively rough surface eats up the tyres faster thereby hastening any demise.

5. Racing: While this may not be a rule, there IS a childish tendency to try and overtake the car in front without fully considering the risks involved. This is especially true when climbing/descending the Ghat sections.

6. Standing water: I have experienced this a couple of times and can turn even a relaxed 100 km/hr cruise into a nightmare within a few metres. Mercifully, I was at 'controllable' speeds of about 90 km/hr and on new tyres.

7. HCVs breaking down anywhere or having tyres replaced on the left lane even though within yards of a layby / tankers watering flowers in the fast lane (!) / oil drums announcing immediate roadworks

[AMATMO]

i am not sure if its the right thread, but just wanted to know
if the three projects are totally ready by now?

1.north south corridor
2.east est corridor
3.the golden quadrangle

[eclectix 1st]

Check it out here Welcome to NHAI

Originally Posted by AMATMO

i am not sure if its the right thread, but just wanted to know
if the three projects are totally ready by now?

1.north south corridor
2.east est corridor
3.the golden quadrangle

[silver_shadow]

the other day i was doing nearly 100 in my ikon on the marathahalli ring road in bangalore when i suddenly heard a noise of metal grating. so i pulled over and found the left front wheel punctured.... i guess you can call that a sudden tyre burst (had a nail in it).

but guess what? no skidding. even at 100 which is still kinda high! what that tells me is that many of those people were going too fast anyway. if my ikon didn't skid at 100 why should a skoda? as mentioned countless times in the thread the speed limit is 80. i've travelled a lot on the expressway and the old NH4 (by bus and car with someone else driving), never driven myself, but i know for a fact that the old highway was the death trap. the new highway is absolutely safe by indian standards. if there are mishaps it's because of rash driving, not because the expressway is unsafe.

on the old highway, you couldn't overtake without getting on to the wrong side of the road. head ons were pretty common back then because of this. and in fact this is the story on every busy highway in india which was just 1 lane in either direction without a divider.

[aaggoswami]

Originally Posted by sunil

No doubt Mumbai-Pune Expressway reduces travelling time between 2 cities, but off late it has become notorius for claiming lives. Last week there were 5 casulities in Indigo & day before yesterday 3 within family in Maruti 800 (Hus-Wife, 2 yr old boy) and fourth one 6 yr old girl is in hospital.

There is no count of lives lost till today on the Expressway.

One of my relative had miraculous escape when his Skoda L&K climbed on dividers and ran 200-300 mtrs over it before coming to halt in a dug up pit for bushes after a rear right tyre burst while going to Pune in the morning.

What effective measures needs to be taken to avoid the accidents ? Comments ? Suggestions ?

Its really not about the Expressway. We have a similar expressway called NE1 between Vadodara and A'bad.

I have observed that Mumbai-Pune expressway is generally misused to test the speeds and dynamic capabilites of cars. Even Automags testers use it at high speed. The Expressway thourghout india was designed for 120kmph and to be on the safe side the speed limit is 80kmph. Generally most of the people do more than 120 wheather they are in Alto or Accord.

This is a safety risk. Expressway cannot be blamed for the casualities. There has to be speed limit that is being obyed by everyone. Yes there are loopholes and the some people end up crossing the roads, but then we have to be more alert and cautious. Your uncle's Skoda's one of the tyre bursted, then how can one find fault the expressway. Probably you uncle was not overspeeding and so he escaped unhurt and thank god for that.

[kaynmantis]

Let us be honest and examine how many of us who have driven in the expressway actually kept to the legal and safe speed limit of 80kmph. Not me, Though I've done 120+ I keep an average of 100kmph. I've been lucky so far. Unless I learn how to wise up, I may end up as statistics.

Often, its not THOSE crazy speedsters. Its me. Any normal person that loves cars and driving will always get the tickle to floor it a bit now and then, and sometimes things goes wrong.

Granted, 80 kmph may seems like crawling on expressway, but its safe, period. Will I wise up? I'll see when I hit the expressway next time.

[dadu]

Even the mfg advise 2-4 PSI more for highway driving

Originally Posted by pgsagar

[bblost]

Originally Posted by pgsagar

I am not sure if I am right, but I was under the impression that tyres' pressure increases as the tyres heat up and air inside it expands, when driven on hot surface roads at high speeds. This heated air would increase the tyre pressure by at least 4-6 psi. Shouldn't then one keep the pressure lower before commencing on a long highway drive?

You are right but

Under inflated tyres have to overcome more friction as they touch more road.
more friction is more heat. more heat is more preasure buildup and then a blowout.

Then there is more tyre flex on underinflated tires.

some stuff found on googling:
google verbs: tire flex heat blow out

How Safe Is Your Car? THE FIRESTONE TIRE CRISIS IS A SCARY REMINDER THAT CARS REMAIN VERY DANGEROUS. HERE'S HOW TO SPOT TROUBLE IN YOUR CAR BEFORE IT HAPPENS--AND PROTECT YOURSELF FROM AN ACCIDENT. Plus, MONEY's guide to the SAFEST CARS ON THE ROAD -

[liberal]

Originally Posted by silver_shadow

the other day i was doing nearly 100 in my ikon on the marathahalli ring road in bangalore when i suddenly heard a noise of metal grating. so i pulled over and found the left front wheel punctured.... i guess you can call that a sudden tyre burst (had a nail in it).

I dont think that is a tyre burst, I have seen case of a Zen I passed by on Mumbai - Nasik highway, it had bits of tyre pieces left behind on the road & a found a part of the rear right tyre missing and skid marks were all over the road.

[silver_shadow]

Originally Posted by liberal

I dont think that is a tyre burst, I have seen case of a Zen I passed by on Mumbai - Nasik highway, it had bits of tyre pieces left behind on the road & a found a part of the rear right tyre missing and skid marks were all over the road.

yea you are right then... but i'd imagine that most people were driving too fast anyway (if they lost control so badly). what happened to the zen?

[agbenny]

For Quadilateral: .:NHAI:.Completed Stretches on Golden Quadrilateral; They update once in few months.

[trakesht]

sorry for the bump, but just came across these figures about expressway and thought that I should share them.

• 10 years
• 1758 accidents
• 7200 injured people
• 444 deaths

and except for 2005 , accidents and deaths have been rising at a rate of 15% per year
A bloody track record, News - City - Pune Mirror,Pune Mirror=

[WDM007]

^^^ Agreed that accidents are rising by 15%. But the traffic is rising by more than 30% everyyear.

So, the relative calculations tell that accidents are actually decreasing.

[ghodlur]

For me the safe speed on Pune E-way is 90 kmph. Ideal, not slow and not too fast. The total e-way is something of 90 odd kms, out of which 20 odd kms are the ghat section. So the balance 70 odd kms are a straight stretch. So an ideal speed of 80 kmph is good enough, but still this speed regulation is not followed.
People tend to think that they are sitting in a rocket once they hit e-way. Once I was driving at 90 kmph in the middle lane and there was a Zen behind me blinking lights asking me to give way when he had the whole fisrt lane. Of course I did not give him the way so he had pass me in the first lane which he did but not without cursing me.