Radar cruise control in the fog

As I said, these rear fog light units have an E-mark which means they have been approved by one of the European country approval authorities. These have an E4 approval E-mark which represents the Netherlands authority. They conform to UN/ECE regulation 38 which provides standards for rear fog lights.

The required color is red as specified in Section 9 of reg 38. The required pattern and light intensity is specified in Section 6 of reg 38.

A rear fog light produces a directional beam and must be aimed so that the beam projects rearward within narrow tolerances.

 

That's when I use my emergency flashers.
Flashing light is more visible in fog.

 

Google something like "driving with hazard lights in fog" to read about the dangers and legal implications of doing that.

 

You had me curious. My search lead to this weather.gov page, stating:

This driver education page lists 10 states that currently prohibit the use of hazard flashers while driving, but all 10 allow an exception for participation in a funeral procession.

The other 40+D.C. prohibit with exceptions for hazards (e.g. fog or reduced speeds as a result of fog,) outright allow or even require the use of hazard flashers while driving in variously-defined hazardous conditions.

(edited for clarity)

 

Because funeral processions are uniquely hazardous????

 

29 U.S. states and Puerto Rico either prohibit or limit the use of hazard lights while driving. The state in which I live prohibits the use of hazard lights in all situations in which a vehicle is moving - only allowed when stopped. Here is a web page that attempts to summarize the state laws: Hazard Light Use - AAA Digest of Motor Laws

Edit: Here is a quote from the "driver education page" you provided a link to: "In other words, you should not drive with hazard lights on, not even in bad weather."

 

@Offline I think we'll have to agree that these regulations simply aren't well harmonized across the country. Looking at your AAA page on the Canada tab, I see that this scattershot result is not limited to the USA.

 

I completely agree with that. Regulations like this are often left up to individual states and provinces instead of being done at a national level.

At least many Toyota models sold in the U.S. currently have amber rear turn/hazard signals although the output level on some Toyota models is ridiculously low and, in my opinion, unsafe. There's no incentive for Toyota to increase turn signal intensity for their vehicles sold in North America simply because rear fog lights have been omitted. Toyota is after all meeting minimum U.S. requirements for rear turn signals.

The only minimum required intensity of a rear turn signal for vehicles sold in the U.S. that I could find says .3 candela - that's 3/10 of 1 candela which sounds crazy low to me. The minimum required intensity for a UN/ECE compliant rear fog light viewed from directly behind is 150 candela which is 500 times higher. The U.S. regs for rear turn signals are very complex due to allowing for variations such as allowing a brake light to also function as a turn signal.

 

True fog lights will shine farther in fog than the blinkers. The driving lights on American cars now aren't fog lights.
At night, in dense fog, I tried turning just the parking lights of the 2005 Prius. I couldn't tell that they were on.

 

No fog in the forecast, but I have spent the weekend with a rented 2019 Camry with the radar cruiser. I still really like the feature though I still don't think I can get the follow distances long enough.

I still have 100 miles to go before I'm done but it should be clear tomorrow morning.

I'll be honest, I really like the car. Plain old twist ignition key plus radar cruise in the same car. Carplay built in sure doesn't hurt. 43mpg without hybrid price penalty. There's a lot to like about this car.

 

Half a lifetime ago, I had understood factory "fog lights" to be decorative lighting, legal in all 50 states, including in a couple states where true fog lights were illegal.

The fog lights I added to my 1986 Accord (from the official accessory brochure, not from the factory) were true fog lights, and were a great supplement to those horrid old standard sealed beams, especially the single rectangular version, with the worst pattern of the four approved configurations.

The factory "fog lights" on one of my later cars, and also on one of my mother's cars, were just decorations. Their light patterns were almost useless. Fortunately the move away from those old standardized sealed beams has brought about much better headlights, making supplement lights less necessary.

 

I installed the same front fog lights from the Honda accessory catalog on an 83 Accord, 85 CRX Si and 86 Accord - quite large, rectangular with black metal housings with a single bolt on the rear that allowed aiming by rotating the light unit on its bracket. They were quite good and remarkably easy to install with their included brackets and harness. I replaced the headlights on all three of those Hondas with Cibie or Hella units with replaceable halogen bulbs. Aerodynamic headlights are pretty but it was nice back then to be able to slap in a pair of standard E-code light units and get vastly improved lighting.

I noticed that the factory fog lights on both our '12 Prius v and '14 Sienna are the same model and have the "E2" E-mark on their lenses which represents the French approval authority. Those who have factory fog lights on their Prius Prime could shine a flashlight on their fog light lenses to see if they have an E-mark. They should be decent if they have one.

I've found that the actual following distances when using DRCC are dependent on the size and mass/density of vehicles ahead. I frequently toggle through all three following intervals with the steering wheel control as I approach and pass vehicles on divided highways but I rarely need to cancel DRCC or use the brake or accelerator pedals. Using DRCC is a learned skill but becomes second nature over time.