A laser is a very narrow beam, so you'd need sophisticated tracking hardware/software to keep the beam aimed at the centerline as the car moved within the lane. You could spread the beam into a wide plane, but then your intensity would drop. Either way, you'd probably be better off with a conventional lamp providing more light near the centerline.

Seems like you'd also have a lot of safety issues if you had a laser pointed forward from the car, even if it was intended to point down at the centerline. Highly reflective stripes or litter could reflect the beam and cause a hazard to the driver or bystanders. The beam could get misaligned, etc.

Micco has very valid point. Something like this would indeed require sophisticated hardware/software to be developed. I think that perhaps some sort of an digital display projected to the windshield may be an alternative. The light intensity could be better maintained (or changed). But again, the tracking for the centerline would be difficult but not impossible. I'm concerned though that in hazardous driving conditions (rain, sleet, snow, hail), any sensors would be thrown off.

thank you for your thoughts

The painted lines seem to dissapear during rainy weather especially at night.
You're right this is a problem, but I'm not sure about you're sollution.
Check
http://www.freepaten...ine.com/5439312.html
Tommy

Well, some states use these things called reflectors.

I think that the real problem might be refractive index. You will need to do some test runs with dry roads and wet roads with and without yellow lines. This sort of idea needs a working model. BUT if you make it work I will buy one.

"This could help drivers with poor night vision."

Glasses should help this condition, known as "night myopia". I'd be worried that the laser would be a point of focus for the driver, and rather than looking well down the road, they would be focused on a red dot a few metres from their vehicle.

I'm not convinced this is a good idea, nor one that could be crowdsourced.

Any headlights bright enough to be legal for road use are more than bright enough to illuminate the centreline of the road. The problem is instead due to the amount of light which is 'lost' in the reflection process, where 'lost' in this case implies 'not reflected back towards the driver'. This could be for several reasons, with the simplest being that the line is simply dirty.

Alternatively, the line itself could be at fault. If the paint behaved as a smooth reflector (ie a plane mirror), the light would be REFLECTED forwards away from the car - no use to anyone. Better is a situation in which the light hits a rough surface and is SCATTERED in all directions, but if it goes in all directions equally you still have the problem that little is returned to the driver. Modern road paint contains small, embedded, REFLECTIVE particles (some of which will have faces directed back towards the driver) in a SCATTERING matrix to give you the best of both worlds.

Either way, a laser will be affected in exactly the same way as standard light and in fact the smaller area decreases the chance of back reflection.

I like this idea for a secondary use: to feedback to the sending unit to gauge driver accuracy....if the sensor fails to pick up the reflectors say ten in a row, a voice yells at the driver "hey idjiot!! get back on the road". that would make driving so much more fun.

it also paves the way for driverless autos, which will be here before flying cars, I think.

Philip H
Modern road paint contains small, embedded, REFLECTIVE particles (some of which will have faces directed back towards the driver) in a SCATTERING matrix to give you the best of both worlds.

Its amazing how an idea like this that identifys a problem ,brings out a comment showing the obsticals you have to overcome with an in depth look at what is going on and how it works.

while thinking on how to coment, leads me to an idea .

the problem is in the paint !
http://www.wisegeek....reflective-paint.htm

what if ALLl those reflective beads could have ALL there reflective faces set facing directly to the angle of the onconing vehicle ?
maybey i should try patening this idea instead of posing it here for all to see,but what the heck if it works it could save a lot of people lives.
if the reflective beads in the paint were magnetic they would all have a north and a south pole and could be lined up in any direction with a magnet pasing over the wet paint as it is being laid.
the position of the magnet in relation to the white or yellow line could detirmine the angle the reflective beads take before it sets
if you ever played with a magnet and iron filings you will know what i mean .

That's a pretty good idea.

I agree that there is a problem but not sure about the practicality of the solution. I do not have a better solution to offer except to paint better lines on the roads.

I would think that water level would affect this as well, could better road drainage be more important?