How do you use the Radar Cruise Control?

PaulWhitt20 · August 16, 2023

I have had a play after reading the manual. P288 onwards

When I press the Cruise Control main switch, I get the green light and Radar Ready. But when I press the -Set button nothing happens. I don’t get a set speed displayed, and the cruise control is not active. I should mention that I have only tried it on single carriage way A roads with traffic, at speeds of up to 50 mph. (Not a situation I would use it. But just experimenting)

Does it only work when on a dual carriage way/motorway when it can detect lane markings?

Thanks

Paul

Lmafudd · August 16, 2023

I think this is my favourite feature. I use it constantly and I know people frown on that so I expect the comments but it helps prevent the 'lead foot' and keep one within the speed limit imho. I wouldn't try it if it was just the dumb old type but the Radar version is ace.

In my UX - Press the Radar/Cruise on button. When at the desired speed press 'set'. The actual speed you are moving becomes the set speed. The 'Res' button is used to resume the previous setting if you have braked. Braking deactivates the cruise mode.

When cruise is active the 'Res' button increases the set speed upwards and the 'set' button decreases the speed. My current car only works in 5mph steps - the only negative of the system I think.

Lane control can be switched on or off with the button to the left of the 'Res' button. I find mine a little jumpy but sensitivity can be adjusted.

Herbie · August 16, 2023

1 hour ago, Lmafudd said:

My current car only works in 5mph steps - the only negative of the system I think.

That's a feature of radar cruise. Switch to standard cruise and they're 1mph increments.

Herbie · August 16, 2023

Just to add to what Charles said above, it's my impression that radar cruise works more on distance than speed, or perhaps they're equally important.

Say you're going through a stretch of roadworks with a 50mph limit on the motorway. You enter the roadworks, set the speed at 50mph and away you go. If the vehicle in front of you is only doing 40mph you'll soon catch it up, but radar cruise will slow your car down to maintain a certain distance between you and the one in front. If the car in front speeds up, so will yours. Or if you pull out from behind the one doing 40, your car will then speed up to whatever you've set, ie, 50 in our example.

PaulWhitt20 · August 16, 2023

That's how I expected it to work, but not tested it on the motorway yet. Would it work on A roads around town or is it a motorway only thing?

When I set the speed I doesn't seem to work.

Herbie · August 16, 2023

Just now, PaulWhitt20 said:

Would it work on A roads around town or is it a motorway only thing?

It'll work anywhere but with A roads you have to be careful on bends because there'll be a point where the car in front moves out of the radar as it goes around the bend. Your car, however, will see that the obstruction has disappeared and the radar reads it as a clear road and can speed up.

rayaans · August 16, 2023

It sounds like you're doing the steps correctly.

Press the cruise button to activate the system and the radar ready / green light will come on

Then whilst on the motorway hit the -set button and it should continue at that speed. Obviously ensure you're not pressing the brake at this point

It does genuinely work anywhere. I use it a lot in town to be honest

Gary H · August 16, 2023

In theory it should work anywhere. I only personally use mine on dual carriageways and motorways which are straighter. I don't recall having ever used it on regular single carriageway roads.

Personally, I wouldn't trust lake-keep assist on single carriageway roads as I think the sensors need to also pick up a line/markings on the nearside - which a number of single carriageway roads lack. In those cases where I've tested it, the system generally doesn't work and will display as such on the dashboard. It's also slightly dodgy when it comes to 'seeing' lines on concrete sections of motorway. I did once try it on the M54, said the system was showing as working but clearly wasn't when the nearside wheels straying over onto the rumble strip of the hard shoulder (both my hands were ready at the wheel to manually correct, may I add!). I've never had any issues with it on tarmac.

As for the radar cruise - it's an excellent feature. This is the first car I've had it on and I'm struggling to understand some of the criticism it attracts from certain quarters (across any car with it - not just Lexus). Whilst it does make the car brake harder than I would with my own foot, it saves all the faffing that I used to do with putting cruise on for a mile or two, then having to slow it down or turn it off when approaching a vehicle going a few mph less. It's particularly useful on SPECS sections of roads where you often find some motorists cannot keep a steady speed. My only real issue with it are indeed the 5mph increments in adjustment. That's a bit silly in my opinion. I turn the system off, adjust my speed and then turn it back on again. I've got it down to a fine art where I can do this in literally a second!

DavidCM · August 16, 2023

With radar cruise you also have 3 options available for the proximity to the car in front.It doesn't have an Audi/BMW mode to allow you to get right up the bumper of the car in front...

rayaans · August 16, 2023

1 hour ago, DavidCM said:

With radar cruise you also have 3 options available for the proximity to the car in front.It doesn't have an Audi/BMW mode to allow you to get right up the bumper of the car in front...

TBH the radar cruise control on the lowest settings in the UX and RX seem to get a lot closer than the VW does. The Golf has been leaving quite big gaps on lowest setting which tempts people too readily to get in the lane and cause it to drop further. Haven't really had that much of an issue with the Lexus adaptive cruise

Spock66 · August 16, 2023

I find it does tend to err on the cautious side and can end up braking when you don't expect it, but overall is better than a traditional fixed speed only cruise control.

Lmafudd · August 17, 2023

18 hours ago, Herbie said:

That's a feature of radar cruise. Switch to standard cruise and they're 1mph increments.

I don't think that option exists in my UX.

ColinBarber · August 17, 2023

11 minutes ago, Lmafudd said:

I don't think that option exists in my UX.

When you turn on cruise control, rather than giving the button a quick press you need to press and hold for a couple of seconds to enable standard CC.

Lmafudd · August 17, 2023

11 hours ago, ColinBarber said:

When you turn on cruise control, rather than giving the button a quick press you need to press and hold for a couple of seconds to enable standard CC.

Thanks Colin. I'll give it a try.

PaulWhitt20 · August 18, 2023

I have been playing with the Radar Cruise Control and managed to get it to work.

It does not work if you are in B mode. (EV only)

If you are using Cruise Control and you select B mode it drops out of Cruise Control without any warning and if you are already in B mode it does not enable the speed setting so Cruise Control does not activate. Again with no warning.

I tried to let it brake for me at a roundabout, but I chickened out and applied the brakes before it did.

At least I know how to use it now if I ever get on a nice quiet motorway.

NemesisUK · August 18, 2023

1 hour ago, PaulWhitt20 said:

I tried to let it brake for me at a roundabout, but I chickened out and applied the brakes before it did.

Have you tried adjusting the distance settings? Set to the longest might better match your braking points?

PaulWhitt20 · August 18, 2023

23 minutes ago, NemesisUK said:

Have you tried adjusting the distance settings? Set to the longest might better match your braking points?

It was on the longest setting. I like to brake smooth and early.🙃

ColinBarber · August 18, 2023

2 hours ago, PaulWhitt20 said:

At least I know how to use it now if I ever get on a nice quiet motorway.

if you are on a nice quiet motorway there isn't a need for radar 😉

Spacewagon52 · August 18, 2023

The radar cruise is excellent for safe and relaxed cruising on a busy motorway. Set it for say, 60mph, then if you follow a car doing 50mph your speed will adjust to their speed. So what? You might say, if the car in front alters their spped up and down then your car will match without you braking or accelerating. By indicating to overtake, the radar is "switched" to 60 mph and you begin to accelerate.

The only odd thing I have found is when a car moves into your lane quite close to you. The radar does not seem to react at first. A good feature really as the car would brake every time a car pulled in front of you.

I will try Colin's suggestion of ordinary cruise on my NX - thanks Colin.

Spacewagon52 · August 19, 2023

I will try Colin's suggestion of ordinary cruise on my NX - thanks Colin.

Yes it works! Thanks Colin! I must get round to reading the manual AGAIN!

stepppy · August 19, 2023

On 8/18/2023 at 8:46 AM, PaulWhitt20 said:

…… I tried to let it brake for me at a roundabout, but I chickened out and applied the brakes before it did.

At least I know how to use it now if I ever get on a nice quiet motorway.

I am confused by this, did you expect it to bring you to a stop/slow down at a roundabout? It’s adaptive cruise control so it would not stop, just carry on as the radar follows a vehicle rather than looking to slow for an approaching junction.

It’s an amazing system, I use mine a lot and not just on motorways, it’s especially good in stop start crawling traffic. When I am coming off a slip road I just flick the lever (Prius) or tap the brakes to disengage as I prefer to take over, then I just tap resume to continue on my way.

I hope this helps 😊

PaulWhitt20 · August 19, 2023

4 minutes ago, stepppy said:

I am confused by this, did you expect it to bring you to a stop/slow down at a roundabout?

To clarify, yes I did expect it to slow down at the roundabout as there was a lorry in front and that had stopped. 🙃 But out of an abundance of caution and not wanting to hit the lorry I braked. 🚛🚙

B mode - Well I use it most of the time as it’s a EV and taking you foot off the accelerator in B mode slows you down and recharges the Battery. In this way you don’t always need to brake at a clear roundabout or junction. Disadvantage is the brake lights don’t come on to tell others behind you are braking so you have to be mindful of that.

stepppy · August 19, 2023

Ahhh I didn’t know there was a lorry in front 😀. Like you I would tap the brakes to disengage as I would prefer to be in control.

I removed my comment about B mode as I suddenly remembered you have the 300e which uses B mode differently to the B mode in my Prius. I thought as I was typing it that I didn’t remember the UX 250h I drove having a B mode, then the penny dropped and I remembered yours is electric.

Sorry for the confusion 😀

Lmafudd · August 20, 2023

On 8/17/2023 at 9:21 AM, ColinBarber said:

When you turn on cruise control, rather than giving the button a quick press you need to press and hold for a couple of seconds to enable standard CC.

Yes it works as you described Colin, although I can't think of any occasion where a static cruise would be used instead of the Radar Cruise! Good to know it works though!