A rant

[rsc]

This afternoon, driving from Gloucester to Cambridge and back in rainy, intermittently foggy, weather, with visibility ranging from OK through so-so to pretty bad, I observed a distressingly (I wish I could say surprisingly) large number of vehicles with their headlights off. A minority, to be sure, but a pretty substantial minority.

Massachusetts passed a law sometime in the last few years mandating that a moving motor vehicle with its windshield wipers on must also have its headlights on. Of course, enforcement is nonexistent, but really, folks, this law shouldn't be necessary; it's depressing that the Legislature found it necessary to legislate what ought to be common sense.

Some of us who have driven in rain for more than, oh, ten minutes have noticed that, when visibility is poor, cars with their lights on are much more visible than those without. Some of us have reasoned from this observation that our own vehicles would likely be more visible with the lights on than not. And then, there's this final link: The better other drivers can see my vehicle, the safer we all are.

Sometimes, if I find myself in such conditions directly behind or ahead of an unlighted vehicle, I turn my lights off and on several times, in the hopes of triggering a thought process like the one above. I did this about half a dozen times today; not a single driver showed any signs of taking the hint. One of the vehicles was an ambulance.

(Of course, it's easy for me, because the Subaru has the feature of automatically turning the headlights off when the ignition is switched off, so I just leave them on all the time. But twisting that wand on the steering column is not really that hard -- if it is, you shouldn't be driving.)

Comments

[bitterlawngnome.livejournal.com]

If you want to do something about it, complain to the DOT requesting that they require Daytime Running Lights on all vehicles. Much of the rest of the world does, but the US ... oh no. The evidence of increased safety and visibility are overwhelming, but the car manufacturers have done a great job of drumming up astroturf objections. https://en.wikipedia.org/wiki/Daytime_running_lamp#United_States

[rsc.livejournal.com]

For some unknown reason (unknown to me, anyway), daytime running lights do not include taillights, which are often just as important as headlights if not more so. Some of the vehicles I noted did in fact have DRLs. (Our car does, and so did my previous car.)

I

[danthered.livejournal.com]

Hi, there. bitterlawngnome pointed me at this post. I'm not only his husband, I'm also CHief Editor of the global vehicle lighting field's technical journal of record.

Most of your rant is absolutely right and completely justified: if it's rainy, foggy, snowy, dusty, smoky, or visibility is elsewise reduced, everyone on the road should have appropriate front and all side/rear lights on. "Appropriate" complicates matters, though; as you've observed, law or no law, too many drivers won't do the completely obvious right thing and put on their full lights (low beams with the attendant ancillaries (parking lights, tail lights, side marker lights, licence plate light, dashboard lights) when visibility is reduced. Add choices and decisions, and more drivers are going to either make the wrong choice or just spend their attention on the car's "infotainment" (shudder) toys instead.

The choice/decision is between DRLs and low beams. DRLs generally do a better job than low beams until visibility is severely reduced (when glare and backscatter become issues), because most DRLs' light distribution patterns are such that more light reaches other drivers' eyes. Low beams are a compromise between the driver's ability to see and other drivers' need to be protected from dazzling glare; many low beams put very little light above horizontal, which is nice for good glare control but means they're not very effective as DRLs if there's much ambient light. Low beam DRLs are one of the legal implementations in North America, because they're easy and cheap for automakers to implement and they're better than nothing.

So in light to moderate rain/snow/fog, technically DRLs + ancillaries (park, tail, side marker, etc) would be best. But practically then we'd be asking drivers to make another judgement call on when to move the headlamp switch one click and when to move it two clicks, and that's too complicated, so it's best if lights-on-with-wipers-on laws are written simply to say "Turn on your damn low beams when it's raining, slob!". All that said, lights-on-with-wipers-on laws have been shown to sigificantly reduce the rate of relevant collisions, so to some degree the requirement seeps into some drivers' minds.

Some DRL systems do and some don't include the ancillaries, and "with" is not necessarily better than "without". In bright sunny conditions, it can be better not to have the tail lamps lit, because tails reduce the visual contrast between brake lights on vs. off. With lower ambient light levels or rain/fog/snow, of course tails and side markers are a help; that's what they're for.

Even the seemingly simple aspects of this actually aren't. Yes, Subaru lets you leave the headlamp switch on and just have the full lights go on and off with the ignition. That's convenient, but it hammers the filaments hard every time the engine is started or stopped, significantly reducing bulb life. But Subaru (and most other makers) specify long-life bulbs as original equipment, so it's no problem, right? Well…no, because LL bulbs give substantially poorer headlight performance (http://dastern.torque.net/techdocs/Bulb_Luminance_Beam_Effect.pdf) (pdf) at night when we need them. For example, the high-performing version of one particular kind of headlamp bulb produces 1700 lumens over a lifespan of 450 hours, and its filament coil is focused such that the low beam reach in a particular headlamp is approximately 85 metres. The long-life version of that same kind of headlamp bulb produces 1460 lumens over a lifespan of 1200 hours, and its filament coil focus is such that the low beam reach in the same headlamp is only about 70 metres. Given the disproportionate number of crashes—especially pedestrian hits—that happen after dark, this is not a good tradeoff. This isn't a problem with HID or LED headlamps, but most cars still have halogen, and while"HID kits" and "LED kits" are easily available, they're all unsafe and illegal.

Re: I

[rsc.livejournal.com]

Wow. That's a lot more information than I knew existed. Thanks.

Add choices and decisions, and more drivers are going to either make the wrong choice or just spend their attention on the car's "infotainment" (shudder) toys instead.

Yeah, and I expect a lot of people have the idea that their headlights are there to help them see, to which of course they contribute nothing in even low-visibility daytime conditions.

II

[danthered.livejournal.com]

Moreover, headlamps and ancillaries don't run for free; assuming the car has mostly bulbs rather than LEDs, using full lights as DRLs is very inefficient—somewhat like opening the fridge door and using the fridge light to read a book. Low beams alone are 120 to 140 watts for the pair. The ancillaries add between 20 and 100 watts to that. The fuel consumption to generate that electricity is substantial enough that General Motors successfully lobbied for permission to have the DRLs disabled when putting their cars through the Federal fuel economy and emissions type-approval tests. It's a fabulous piece of möbius argumentation: GM since 1997 puts DRLs on every vehicle they sell in the US; they do not permit buyers to say "no thanks", they do not equip their cars with a DRL-off switch, and they do not permit their dealers to disable them even though DRLs aren't legally required in the US, but DRLs aren't legally required in the US so they ought to be optional during the emissions and fuel economy tests. Whee!

But wait, there's more: DRLs that do not automatically put on the ancillaries, particularly with today's digital always-lit dashboards, encourage misuse or nonuse of the vehicle's full lights at night, which creates real safety problems (no tail lamps or side markers after dark makes the car invisible from sides/rear; no full-intensity headlamps after dark gives the driver inadequate seeing, and DRLs implemented by running the high beams at half power are extremely glaring after dark).

The real solution is to fully automate the lights with an ambient light sensor and a tie-in to the windshield wipers; when the wipers are operated for more than 30 seconds, the full lights come on—this is a zero-dollar line of code in the body control module of even the simplest of today's cars, but I can't think of any cars that do it. And when ambient light levels drop below 1,000 lux, the full lights are turned on automatically; many cars already have the needed ambient light sensor. But automakers like being able to charge extra money for the Comfort and Convenience Package or the Driver's Preferred Equipment Group, available on de luxe trim levels of the vehicle, which for $6,157 gets you your power-operated ashtray, your heated power window switches, your smart cupholders, your color-keyed rearview mirror bracket, your memory floor mats, and your automatic lights. And while automakers are happy to put DRLs on cars in the US for branding, style, or extra-profit reasons, they fight tooth and claw against a mandate. "Not cost-effective! No proven benefit!" they bleat—same as they do about proper turn signals (http://acarplace.com/cars/turn-signals/).

Beyond that, Americans tend to behave like Americans: US seatbelt usage rates have long been lower than those in the civilised world, and seatbelt must-use laws were resisted for decades on spurious grounds of infringement of freedom. The same thoughtless babble is used against DRLs; there are groups and websites raving in complete, willful, proud ignorance about how DRLs are a menace not only to safety but to liberty.

Re: II

[rsc.livejournal.com]

The real solution is to fully automate the lights with an ambient light sensor and a tie-in to the windshield wipers

Speaking of which, and slightly off-topic, I have long wished for a feature whereby the car could automatically determine whether and with what frequency the wipers need to run. No more "Oh, it's raining a bit harder now, better turn up the frequency. Oh, damn, now they're scraping."

Re: II

[danthered.livejournal.com]

Those wipers have already existed for about two decades. They're available on a slowly-increasing number of vehicles, mostly high-endy ones. There used to be retrofit kits—RainTronic from Hella, and Rain Tracker from an American outfit, but the Hella kit has been discontinued for several years and the Rain Tracker site (http://rainsensors.com/2015/11/10/rt/) tells the sad story of that kit's discontinuation in 2015. I wish I had them on my car, too.

RE: Re: II

[rsc.livejournal.com]

Yeah, I thought it might be an option on something high-end. Not likely in my future.

Re: Re: II

[danthered.livejournal.com]

Fortunately for those of us who don't drive snooty cars, this stuff (https://www.amazon.com/dp/B000BVRZ74/?tag=2402507-20) works surprisingly well when applied as directed (which isn't difficult).

RE: Re: II

[rsc.livejournal.com]

Yeah, I thought it might be an option on something high-end. Not likely in my future.