Warm Weather and Increased Accident Rates

How spring and summer affect safety on the roads and what can be done to mitigate the damage.

Safer than winter – but not as much as you think

With average mid-temperatures above 50°F, clear skies and mild breezes, there is no wonder that both pedestrian and motor vehicle traffic increases visibly in April – after all, some sun exposure seems more than earned after long months of winter. Moreover, with spring in full swing and summer around the corner, it may feel safer for motorists to use their vehicles. Indeed, snowstorms, icy roads, and early nightfall can all lead to hazardous road conditions. For those who think, however, that the roads get universally safer as the weather gets warmer, hard data available on this matter will provide a rather surprising insight.

Last year, economists Benjamin Leard and Kevin Roth released results of a truly massive data analysis they had conducted in order to study the effects of climate change on road accidents. The analysis included information from 46 million police-reported accidents from 20 states, daily travel logs of 207,455 households, and weather reports from 2,607 weather stations in the United States between 1990 and 2010. The study found that although traffic accidents do increase during winter months, especially on rainy days or when the temperature drops below freezing point, those collisions usually involve injuries or property damage. However, the study also found that on a day with temperatures above 80°F, the number of fatal accidents rises by about 9% in comparison with a day of 50°-60°F. The authors stated that this interaction had not yet been analyzed in depth. What may be, then, some of the suspected causes of the increase in motor vehicle accidents with the onset of warm weather?

DST strikes again

One of the prominent factors seems to be the daylight savings time switch. According to a study conducted by a group of researchers at the University of Colorado, deaths related to traffic incidents increase by a statistically striking factor of 17% on Monday after the spring time change. This conclusion was calculated after analyzing the data on traffic accidents during daylight savings time throughout a 10 year period, which seem to make the study reliable and conclusive. Moreover, a spike in accidents was noted over the whole week after the time switch. It has been suggested that the reason might be lower visibility – the drivers set off earlier in comparison to previous months and therefore it is darker than they got used to. Nevertheless, it cannot be overlooked that the increase in motor vehicle incidents may also be attributed to the fact that our bodies’ circadian rhythms are a fine-tuned mechanism and a sudden change of an hour, small though it may seem, can notably affect our attention and decision-making skills, making us more susceptible to traffic dangers.

Check tires to improve safety

Another element mentioned in relation to the spike in accidents during warm weather relates to vehicle maintenance, especially adequate tire pressure. The relation between tire problems and motor vehicle accidents is considerable. According to the data provided by the National Highway Traffic Safety Administration, NHTSA, tire issues were a factor in accidents that left, in total, 116,000 injured and almost 3,400 deaths between the years 2005 and 2009. The problem is deemed to be so serious that a couple of years ago NHTSA issued a special consumer advisory, urging motorists to take proper care of car tire maintenance. The advisory stated: “Underinflated tires spinning on hot asphalt for extended periods of time can be a recipe for disaster … Motorists should also be aware that aging tires and hot weather can be a potentially deadly combination, as older tires are more susceptible to heat stress, especially if they are not properly inflated”.

Seasonal challenges

Other factors that contribute to the increase of warm weather accidents are more obvious. One of them is increased traffic, both vehicle traffic, and pedestrian traffic. More people on the road means more opportunities for things to go wrong. This is especially true during summer vacation months when there are not only more drivers on the road, there are more inexperienced drivers on the road. People who only drive occasionally are more prone to make mistakes and cause potentially dangerous situations. What is more, those drivers have to deal with a set of seasonal challenges. One of them is seasonal growth – with more sun and spring rains, vegetation starts flourishing which may contribute to limited visibility in critical places such as sharp turns or crossroads.  The problem of limited visibility is also present due to sun glare – because of the position of the earth relative to the sun, sunlight that is reflected from the surface of the road may get right into the driver’s eyes, temporarily blinding him. If it happens in a critical moment, the results may be disastrous.

As the day grows longer and sunnier, we can expect to see more and more traffic on our roads. Drivers do well to remember that although the conditions warm weather brings seem to be safer than those experienced during winter months, they nevertheless entail a set of unique safety hazards. Keeping that in mind will allow them to take all the necessary precautions and enjoy spring and summer without any unnecessary incidents.