Highways and Highway Transportation

by George R. Chatburn

Speedometer.

—Every automobile should be equipped with a good speedometer. Speed limits are known to most drivers and if constantly stared in the face by good clear speedometer numbers they are not so likely to exceed them as if they depended entirely upon a sense of velocity, which is merely relative at the best. A motorist is driving along a country highway at a speed of 25 miles an hour, say, when he comes to a village with a sign out, “Speed Limit, 15 miles.” He slacks to that speed by speedometer but feels he is only traveling 5 or 10 miles an hour. Railroad companies found it advantageous to equip their locomotives with self-registering speedometers in order to reduce the number of accidents due to speeding. The automobilist with a speedometer before him has no excuse, at least, for speeding.

Bad Roads Cause Accidents.

—It is not always the fault of the driver or the vehicle that there is an accident. The roads may be at fault, and while careful driving may decrease the number it can not eliminate all.

Slipperiness is hard to combat. This will vary of course with the types of road, with grades, and with height of crowns. But even a pavement, which in dry weather is perfectly safe, will, when it becomes moist, especially if there is a small amount of dust or clay on it, be extremely slippery. Earth roads when they are wet on top and hard below are very treacherous. All types become slippery in the winter when there is ice and snow. A thorough flushing of pavements, which will remove surplus dust and clay, preferably done at night, is a good remedy for slipperiness. The use of sand or cinders on turns is sometimes resorted to where absolute cleanliness can not be obtained by flushing. Extra precautions by the drivers over the slippery roads and streets is always a good thing. The investigations of the Maryland Highway Commission indicate that about 20 per cent of all the accidents can be attributed to wet and slippery roads.

In the construction of roads high crowns should be avoided. On earth roads the crowns should never exceed one inch per foot and if the road is one that is much used and carefully maintained so that it is hard, should be about one-half inch per foot. A crown of one inch to the foot is equivalent to an 8¹⁄₃ per cent grade down which vehicles will easily run and off which they will slide in slippery weather. Vehicles seek the center of the road when the crown is high both for comfort and safety but two passing vehicles can not be there at the same time. On hard pavements a quarter of an inch per foot will furnish ample drainage, and that is all the crown is for anyway.

Embankments and Guard Rails.

—Too many roadways are built on narrow embankments and often there are no guard rails. The embankment should always be wide enough to accommodate the traffic with an ample factor of safety. It is not uncommon for vehicles to slide off embankments with fatal results. The writer has before him a recent newspaper clipping of one such case where a bus slipped off the roadway and toppled into the ditch killing one man and injuring several others; the busman had no indemnity insurance. Chains on the wheels of the bus or heavy guard rails might have prevented the accident.

The danger from sharp turns

in roads is so well recognized that state systems are now specifying a minimum radius of 200 feet and when practicable laying curves out very much flatter. The pavement is also being widened at the turns so as to allow the same turning radius on the inner as on the outer track in order that the temptation for vehicles to cross over to the other track may be lessened.