I was wondering if using parking lights for daytime driving would not be a safer measure as rear taillights as well as front lights would be visible for others to see rather then just the front lights of DRLs. – Gerry
You’ve touched on my favourite automotive peeve.
Canada followed some Scandinavian countries in making Daytime Running Lights (DRLs) mandatory. I heartily endorsed the move and believe it to be a significant safety factor – if done correctly!
But in bowing to pressure from companies building cars for the American market, where they still live in the dark ages regarding their views toward many mandatory safety and other regulations, Canadian regulators allowed manufactures to activate the DRLs along with the instrument panel lights. As a result, many popular cars – not just American cars, but so-called “imports” that are built in America, fool people into thinking their headlights are on when they are not.
Drivers get into their vehicles in low light conditions and, when they see lights on the dash and out the windshield, think: a) their headlights are on and b) their taillights are, when they are not.
Early the other morning, while out for a walk, I witnessed the resulting danger first-hand, again. Dawn was just breaking and visibility was poor due to the lack of light and fog or early-morning mist. Someone driving a new, popular compact SUV built in North America, wearing the nameplate of an Asian manufacturer, stopped at an intersection to allow me to cross.
I noticed the DRLs were on but not the headlights. I also noticed the glow inside from the instrument panel lights. As that person accelerated slowly away, I noticed no taillights – I couldn’t even make out the licence plate because it was so dark. A few seconds later, a second vehicle passed, accelerating quickly away from the same stop sign. I was able to identify it as a recent-year American car. It too had the DRLs and instrument panel lights glowing, but no taillights.
Just as the second car was about to disappear into the darkness, its brake-lights came on as it was obviously braking heavily. It had come upon the first car and did not see it until the last second for two reasons: a) its headlights were not on and b) the taillights of the vehicle ahead were not on – a dangerous combination.
Now, to your question. Yes, I believe including the taillights in the DRL circuit would be a good idea – but I think a better one would be to make sure the instrument panel lights are not.
Cars and computers
My husband and son were talking about cars over dinner the other night and I overheard mention of a computer. I wanted to ask them what a computer had to do with cars, but did not want to interfere in this father/son bonding moment. So I’ll ask you: what does a computer have to do with a car? – Maryanne
Computers have quite a lot to do with cars. Today’s automobiles have more computing power than some of the ships in the early space programs.
There are actually a number of different electronic control units (ECUs) scattered throughout a modern passenger vehicle. They receive information from a wide variety of monitors and sensors, process that information and direct various devices and systems accordingly. These various computers and sensors are connected by a wired (as opposed to wireless) network known as the Controller Area Network or CANbus.
Individual ECUs control everything from when a transmission shifts to how the air conditioning system works. Thousands of data points are involved reporting on such things as temperature, pressure, the position of the brake pedal and steering wheel. As many as 2,000 signals are passing through the CANbus at any given moment.
I recently read a perfect example of how this works. Many minivans have power sliding side doors. When you press a button to close one, the ECU known as the Body Control Module accepts that command, but before activating the motor that opens and closes the door, that “computer” checks via the CANbus whether the vehicle is stopped and the transmission is in park.
If that is the case, it sends a signal to close the door. But if there is a sudden hike in the amount of electricity the motor is using, as would be the case if a sensor reported something like a hand or finger blocking the door, the ECU reverses the motor and opens the door to prevent injury.
Send your automotive questions to Richard Russell at firstname.lastname@example.org