Most head­lights not up to the job

Lesotho Times - - Motlo -

WASH­ING­TON DC — There may be a rea­son why peo­ple have trou­ble see­ing while driv­ing at night, and it’s not their eye­sight.

A new rat­ing of the head­lights of more than 30 mid­sized car mod­els gave only one model a grade of “good.” Of the rest, about a third were rated “ac­cept­able,” a third “mar­ginal” and a third “poor”.

The dif­fer­ence be­tween the top and bot­tom­rated mod­els for a driver’s abil­ity to see down a dark road was sub­stan­tial, ac­cord­ing to the study re­leased yes­ter­day by the In­surance In­sti­tute for High­way Safety, an in­dus­try­funded or­gan­i­sa­tion that eval­u­ates au­to­mo­tive safety.

The LED head­lights in the top trim level Toy­ota Prius V — the only one of 31 mod­els tested to get the “good” rat­ing — were able to il­lu­mi­nate a straight road­way suf­fi­ciently to see a pedes­trian, bi­cy­clist or ob­sta­cle up to 118 me­tres ahead. At that dis­tance, the ve­hi­cle could be trav­el­ing up to 120km/h and still have time to stop.

But halo­gen head­lights in the BMW 3 se­ries, the worst-rated ones, were able to il­lu­mi­nate only 39 me­tres ahead.

At that dis­tance, the ve­hi­cle trav­el­ing at 60km/h would barely have time to stop, ac­cord­ing to the study.

That’s im­por­tant be­cause about half of all road fa­tal­i­ties hap­pen at night or dur­ing dawn and dusk when vis­i­bil­ity is lower.

The rea­son for the big per­for­mance gap is that there’s a lot more to how well head­lights help driv­ers see than merely the bright­ness of the bulb or even what type of bulb is used, said David Zuby, the in­sti­tute’s ex­ec­u­tive vice pres­i­dent and chief re­searcher.

“We found the same light bulb, de­pend­ing upon what re­flec­tor or lens it’s paired with and how it’s mounted on the ve­hi­cle, can give you very dif­fer­ent vis­i­bil­ity down the road,” he said.

It gets more com­pli­cated. The re­port showed that you can’t buy a more ex­pen­sive model or add an ex­pen­sive tech­nol­ogy pack­age and nec­es­sar­ily ex­pect to get bet­ter head­lights.

The halo­gen head­lights in the eco­nom­i­cally priced base model four-door Honda Ac­cord, for ex­am­ple, earned an ac­cept­able rat­ing while halo­gen and LED head­lights in two pricier Mercedes-benz mod­els were rated poor.

Zuby said with no re­li­able clues such as the price of the car or the type of light, it’s hard for mo­torists to fig­ure out which ve­hi­cles will pro­vide the safest vis­i­bil­ity. He rec­om­mended car buy­ers check the in­sti­tute’s rat­ings on the In­surance In­sti­tute for High­way Safety web­site.

Five dif­fer­ent ap­proaches The re­port comes as halo­gen bulbs are be­ing re­placed by high-in­ten­sity dis­charge and LED lights in many ve­hi­cles. Head­lights that swivel with the car’s steer­ing to help see around curves are also be­com­ing more wide­spread. While these changes can have ad­van­tages, they don’t guar­an­tee good per­for­mance, the re­port said.

Re­searchers tested the head­lights af­ter dark at the in­sti­tute’s test track in Ruck­ersville, Vir­ginia. A spe­cial de­vice mea­sured the light from both low beams and high beams as the ve­hi­cles were driven on five dif­fer­ent ap­proaches: trav­el­ing straight, a sharp left curve, a sharp right curve, a grad­ual left curve and a grad­ual right curve. Re­searchers also eval­u­ated head­lights for ex­ces­sive glare.

Zuby said they were sur­prised to find how much head­lights var­ied from the base model to higher trim or accessory pack­ages.

Eighty-two dif­fer­ent head­light sys­tems were avail­able for the 31 cur­rent mod­els as- sessed in the study.

To get the top-rated head­lights in the Prius V, cus­tomers would have to spec­ify the ad­vanced tech­nol­ogy pack­age, which is only avail­able in the top trim level. Stan­dard halo­gen lights with­out high-beam as­sist in less ex­pen­sive Prius V trim lev­els re­ceived a poor rat­ing.

High-beam as­sist au­to­mat­i­cally ad­justs the head­lamp range for the dis­tance of ve­hi­cles ahead or on­com­ing traf­fic.

Toy­ota of­fi­cials de­clined to com­ment, and BMW of­fi­cials didn’t im­me­di­ately re­ply to a re­quest for com­ment.

Mercedes-benz said in state­ment that it was “greatly sur­prised” by the test, and re­mains “con­fi­dent our light­ing sys­tems pro­vide im­por­tant safety ben­e­fits for real world con­di­tions”.

Zuby said gov­ern­ment stan­dards for judg­ing the per­for­mance of head­lights “are es­sen­tially un­changed” since they were set back in the 1960s.

“They mea­sure the light com­ing out of the light source — right in front of the light bulb, in essence — and don’t look at how the light is pro­jected down the road, which is what our tests do,” he said.

The in­sti­tute hopes its study will en­cour­age the Na­tional High­way Traf­fic Safety Ad­min­is­tra­tion to im­prove stan­dards, or in­spire au­tomak­ers to make bet­ter head­lights on their own, Zuby said.

— AP

Toy­ota Prius V with ad­vanced tech­nol­ogy pack­age was the only model in the study to earn a ‘good’ rat­ing.

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