I always drive with my lights on

I always drive with my lights on

You can argue whether or not having lights on in the daytime is safer or not. I think it is:

There is no sensor that will 'know' its cloudy or foggy and that lights will help you to be seen. Because of this, I am in the habit of driving with my lights on all the time.

The number one thing that annoys me about my current car (a Subaru) is that it assumes that if your lights are on, it must be night, and therefore it dims all of the controls. This means that in the daytime, I can't see the clock or any of the other 'dimmable' controls (radio station, etc.) unless I temporarily turn off the lights. "Is the A/C on? I don't know. Give me a minute while I cup my hands around the control to make it dark enough and then put my face right in front of the tiny orange LED which you can only see from straight-on over the console. I still can't tell. Let me turn it on and off a few times... yeah, I think that's on. Yes, there's definitly more drag on the engine... it must be on. Gosh... I've had a crash! Sorry officer. I was just trying to see if the A/C is on..."

Ok, I'll get to the point:

I just saw a video in which control of the lights of the Model S was demonstrated (on a beta). When you turn on the lights, the screen goes into 'night mode'. I would like to suggest that this change be made configurable. I don't want my car to be in 'night mode' all the time just because I want to have the lights on. I would suggest that if there is a light sensor in the car, that its output be used to determine night mode rather than using the lights on/off setting. If there is no sensor, at least have an easy way to leave the screen in 'day mode' even though the lights are on.

Having a car that 'knows you' is great. Having a car that thinks it knows you (and insists on having its way) is not.

Schlermie | 30 mars 2012

The Model S has LED Daytime Running Lights (DRLs) that are on all the time.

EcLectric | 30 mars 2012

Thanks Schermie. I didn't see that. I'll leave the headlights off,then. The reason I got fired up is that I noticed the car making assumptions about what was going on and forcing something to happen that the driver might not want (like my Subaru does).

EcLectric | 30 mars 2012

Sorry Schlermie. Left out the 'l'...

I like LED tech a lot. I'm using dimmable LEDs in my kitchen. The incandescents used to burn out every 6 months. The LEDs use 1/10th the power and have lasted over a year so far... They also dim with better 'resolution' than the incandescents (and silently).

jbunn | 30 mars 2012


Off topic, but I'm a big halogen fan for the dimming and color of light. I'm switching circut at a time as the halogens burn out to LED. I like it a lot. I may never need to replace them, and they dim well. One difference is halogens dim to candelight color. LED's dim to moonlight. Both nice.

flar | 30 mars 2012

According to one of the employees at the recent Model X showing at Santana Row the Model X prototype had light tape instead of diffused LEDs for its running lights. The entire "lower eyelid" of the light assembly is a glowing tape (like the type used for the suits in Tron: Legacy). You can see them lit up on the "click and drag" picture on the Model X page with the Model S DRLs next to it (note that both cars also have their headlights on in that picture so what you are comparing is the lit trim around the headlight itself)...

stevenmaifert | 31 mars 2012

CA and FL (and maybe some other states) require your headlights (not daytime running lights) to be on when it's raining. This causes the nav display in my Camry Hybrid to switch to nighttime mode, but thankfully there is a manual override. Hopefully, the S will have one too.

DavidG | 31 mars 2012

EV's reduce noise and air pollution, but when everyone uses DRL, we waste energy and add to light pollution. With Los Angeles being the home of the 12 lane parking lot, we have a unique perspective in oncoming glare. Be kind to your fellow drivers and don't DRL. Please.

DRL should be reserved to emergency vehicles only. They must and need to stand out. We don't.

DavidG | 31 mars 2012

OK, motorcyclists need DRL too.

Volker.Berlin | 31 mars 2012

DavidG, I do not share your opinion. To the contrary: Driving with the lights on is much safer than driving with the lights off, in my opinion -- although the effect may in fact be opposite if there is no consensus and some drive with lights while others drive without. Also, the main lights may, under rare circumstances, e.g., when not properly adjusted, blind oncoming traffic even during day time. And they do need some energy.

Having this said, dedicated DLRs are a very bright (pun!) idea. They are constructed such that the car can be recognized more easily, without adding glare. Since their only purpose is "passive" visibility, and they are not meant to "actively" illuminate anything, nothing can go wrong with their adjustment, and they need very little energy. If you are worried about energy, forgo one trip that you planned, and you have saved enough energy to do all other trips that year with DLRs on.

On top, DLRs reduce the problem that a car without lights becomes even less visible among cars with lights. More and more cars have them standard so that it's no longer up to the driver to decide driving without any lights. A very good thing IMO.

Vawlkus | 2 avril 2012

Maybe Tesla can steal a page from Ford on this one. I always drive with my headlights on because I want to do so. The instrument panel in my car has an ambient light sensor separate from those headlights, so it brightens and dims my instrument panel based on the light detected. Works pretty well IMHO.

Chinook234 | 6 avril 2012

In Norway, all cars is delivered with headlights on as a default. You shall have light on always. It's the law.

Jason S | 6 avril 2012

The S has LED DRL that are separate from the headlights. From what I can tell, the wipers and headlights are automatic with probable manual override.

So I really expect it'll just work automatically. Lights & wipers come on at same time for rain and DRL cover every other circumstance. Lights will prolly turn on for any darker than some threshold -- tunnels, garage, etc.

Tom A | 6 avril 2012

Vawlkus: yes, my Ford product, a 2010 Mercury Mariner hybrid, has separate sensors for the headlights and interior lighting. The instrument panels and such will switch to high or low brightness depending on the ambient light within the vehicle, completely independent of the headlights. The converse is also true, where the headlights turn on or off automatically, completely independent of the interior lighting. It's great.

Vawlkus | 6 avril 2012

I think I'll keep my Mustang Tom :P

Tom A | 6 avril 2012


DallasTXModelS | 8 avril 2012

The last 5 vehicles I've owned, all Dodge, have the same kind of dimmer on the gauges and other dashboard lights. The dashboard lighting and video screen(navigation as well)dim or switch to night mode when the headlights or windshield wipers are turned on. To override this feature the rolling dimmer switch has a stop between full bright and dome light called parade setting which enables the dashboard lights to remain bright when the headlights are turned on in bright sunlight to be used in a parade or funeral procession. This feature was also on the previous 3 GM cars before the Dodge vehicles.

stephen.kamichik | 10 avril 2012

In Canada, daytime running lights have been mandatory since 1988. They make cars highly visible. I think they are great idea.

Supergreekster | 10 avril 2012


Nearly all published reports indicate DRLs reduce multiple-vehicle daytime crashes. A study examining the effect of Norway's DRL law from 1980 to 1990 found a 10 percent decline in daytime multiple-vehicle crashes.1 A Danish study reported a 7 percent reduction in DRL-relevant crashes in the first 15 months after DRL use was required and a 37 percent decline in left-turn crashes.2 In a second study covering 2 years and 9 months of Denmark's law, there was a 6 percent reduction in daytime multiple-vehicle crashes and a 34 percent reduction in left-turn crashes.3 A 1994 Transport Canada study comparing 1990 model year vehicles with DRLs to 1989 vehicles without them found that DRLs reduced relevant daytime multiple-vehicle crashes by 11 percent.4

In the United States, a 1985 Institute study determined that commercial fleet passenger vehicles modified to operate with DRLs were involved in 7 percent fewer daytime multiple-vehicle crashes than similar vehicles without DRLs.5 A small-scale fleet study conducted in the 1960s found an 18 percent lower daytime multiple-vehicle crash rate for DRL-equipped vehicles.6 Multiple-vehicle daytime crashes account for about half of all police-reported crashes in the United States. A 2002 Institute study reported a 3 percent decline in daytime multiple-vehicle crash risk in nine US states concurrent with the introduction of DRLs.7

Federal researchers, using data collected nationwide from 1995-2001, concluded that there was a 5 percent decline in daytime, two-vehicle, opposite-direction crashes and a 12 percent decline in fatal crashes with pedestrians and bicyclists.8 However, a 2008 federal study concluded that DRLs have no significant effect on either of these crash types.9

EcLectric | 10 avril 2012

I had one experience that convinced me that having lights on is safer. I was at a stop sign waiting to pull out onto a 30 mph street. It was early morning and slightly foggy. A gray BMW appeared suddenly to my left (going about 40) as I was about to pull out. He had his lights off and the gray car blended in nicely with the fog and if I hadn't waited 1/2 second before pulling out, he would have T-boned my little MR2 on the driver's side. So, I guess sometimes he who hesitates... lives!