This is what George is talking about: http://hdradio.com/get-a-radio/new-car/lexus

 

I was SO BUMMED to learn that the 4IS doesn't generally come with this system. It's an available option, but the dealer's in WA very rarely order IS with this option. I looked into ordering a new IS with it, and it'd take 6 months!! Sounds like it's not all it's cracked up to be? Seattle drivers are probably just as aggressive as LA drivers. Sounds like I wouldn't be using it as much..

 

You'll find that this is a hard to come by item from most manufactures. Before I had decided on my GS I found that M37/M56 Infinities had this option more than any other competitor (though I didn't look very hard into BMWs). It's virtually unheard of on the A6, as of the beginning of June, there were only 2 with DRCC (ACC) in CA while there were 100's of similarly built cars without it.

Santa Monica Lexus has a completely tricked out F Sport with DRCC that was special ordered and never picked up, they said they would offer an amazing deal on it to get rid of it. Maybe check with them, then wait until the 15's have been out a few months and check again to see how much they have come down in price. And one reason the IS could take 6 months is the changeover to the 2015 production which should occur anytime in the next month or two.

From the people I know who have DRCC in their car, they love it and drive with it on 90% of the time. Hell they set their car for 80 on side streets and just stay behind someone else to make sure their car doesn't leap ahead. You just can't expect it to think ahead and ensure you drive rationally. It cannot predict when you'll suddenly change lanes and be behind a group of cars that are stopped or are stopping quickly leaving very little room for you to stop. You still have to use common sense and pay attention to the road.

 

These systems are evolving, they will only get more capable. Full autonomous driving to handle the scenarios you describe requires additional imaging sensors as input to the system. The more advanced Mercedes Distronic + systems add stereo cameras.

I could not leave the 2014 Lexus system engaged for 90% of my driving. Using a high set point on side streets is not recommended. Here are the "official" limitations:

Situations unsuitable for dynamic radar cruise control

Do not use dynamic radar cruise control in any of the following situations. Doing so may result in control of the vehicle being lost and could cause an accident resulting in death or serious injury.

- In heavy traffic.

- On roads with sharp bends.

- On winding roads.

- On slippery roads, such as those covered with rain, ice or snow.

- On steep downhills, or where there are sudden changes between sharp up and down gradients.

- At entrances to expressways.

- When weather conditions are bad enough that they may prevent the sensors from functioning correctly (fog, snow, sandstorm, etc.).

- Where buzzer can be heard often.

- When towing a trailer or emergency towing.

When the radar sensor may not be correctly detecting the vehicle ahead. Apply the brakes as necessary when any of the following types of vehicles are in front of you. As the sensor may not be able to correctly detect these types of vehicles, the proximity alarm will not be activated, and an accident may result.

- Vehicles that cut in suddenly.

- Vehicles traveling at low speeds.

- Vehicles that are not moving.

- Vehicles with small rear ends (trailers with no load on board etc.)

- Motorcycles traveling in the same lane.