A new Peoples' Car?

[Bicycle Bob]

Light timing with more than a few intersections, cross streets, two-way streets and other variables becomes an exercise in compromise, not perfection. However, it would not be hard to add a string of LEDs beside the road to show the correct pace to make the next light, or encourage gentle stops.

[ShadeTreeMech]

I saw a very inexpensive system for light timing in Texas a few years back on a long straight road close to a city. It was a sign informing you to average 40 mph to go through all the lights without stopping. And it worked quite well.

[aerohead]

Originally Posted by Patrick

A cloverleaf at every intersection would require a lot more land and pavement, upping the expense a lot. It wouldn't be practical in an urban setting like Manhattan, where land values are sky high.

Why can't they time a left turn light?

The time required to process the left turn signal traffic creates the bottleneck for all other lanes,essentially making synchronization impossible.
You may have observed dozens of vehicles idling at a stop while only a few vehicles make the left turn.
It's pure entropy.We can't afford the convenience of the few to overshadow the larger issue.
As to extreme urban environments,it would be better for the few to sacrifice a portion of their time by rounding the block clockwise to orient themselves in their desired direction,rather than ask the majority of traffic to consume their fuel at a stop.
Flowing traffic is real wealth,whereas property values are an arbitrary and artificial construct.

[aerohead]

Originally Posted by Patrick

We have four roundabouts in my town. You have to slow to about 20 mph to make it around the curve, but that's a lot better than coming to a full stop at a 4-way stop sign or light. Yes, sometimes you have to stop because of traffic coming around in front of you, but I'd estimate that about 50% of the time I've been able to just cruise right into the curve and out on my chosen street. It does take up quite a bit more land than a regular intersection, though (but not nearly as much as a cloverleaf would).

Patrick,I agree that the roundabout is 'way out ahead of nothing',but I'm trying to envision an infrastructure which can maintain momentum ( all of it ).
Mixing arteries and veins is a delicate matter.
We have a century of mediocre road design to remedy.
All traffic engineering manuals clearly spell out the relationship between conservation of momentum and efficiency.The physics is simple.
I'd like to see the experiment played out as we see in electronics,and other fields of technology.

[aerohead]

Originally Posted by Thymeclock

We think of saving gas as a priority, but we may not be thinking of the unintended consequences. Cloverleafs and traffic circles (rotaries, roundabouts) do increase the amount of miles driven. (Every little bit of additional distance traveled adds up.) It may keep traffic moving, but it won't necessarily save fuel.

Also, if you are making mostly right turns, but virtually never making left turns, your steering and suspension will wear unevenly over time. This tends to be the case already with having the "right turn on red" option (which is better than not having it). I find myself favoring routes that encourage making more right turns.



It usually requires a separate lane. Here in suburban NY left turn arrow signals are timed, but some people dawdle and poke, and often only half the line of cars waiting to go through the intersection actually get to proceed due to inattentiveness. Even the best timed traffic signals won't arouse drivers who are habitually asleep at the light.

Thymeclock,I hear what you're saying about the extra distance,but I what strikes me,is that you're traveling the extra portion at twice the mpg which more than offsets the additional travel.
That's the whole point of the synchronization.All vehicles obtain the urban mpg of a hybrid,with no change to the vehicle.
The American 'fleet' is returning only 17-mpg even though the cars can get around 28-mpg.
The difference is in the congestion,much of which can be ameliorated by abandoning the left turn.
During World-War, II Americans were obliged to drive no more than 35-mph in order to strengthen the war effort.
It's my opinion that motorists can be made to feel patriotic about a little inconvenience.

[aerohead]

Originally Posted by daring4

What about all the diesel fuel burned to build new cloverleafs, roundabouts, etc. New intersections dont just pop up! I drive a 45,000 lb truck for work, it gets about 3 mpg. We have two for every crew, and this is just to repair electric utility lines!

Road construction must use incredible amounts of fuel to build a road for us to get 1mpg better!

Just shut it off and coast if you can, turn it off at red lights, thats how to save fuel!

I have two original peoples cars, a 62 beetle and a 65 type 3, they are cool but I'm thinking something based on the Yaris would go far.

Daring,you might consider the cloverleaf as the Light-Emitting-Diode of intersections,where a dedicated left-turn lane intersection is a whale-oil lamp.
The efficiency in lumen output and energy consumption between the two would be symbolic of the difference between the cloverleaf and the traffic congestion created at the traffic light.
The U.S. is in an ambitious plan to lose the incandescent lamp,moving on to the compact flourescent and LED.The payoff comes after the investment.
If Earth is at its half-life,then the Sun won't red-dwarf for another 4.5-billion years.That's a lot of time to save fuel with more efficient intersections,or end things as you know them.
In a capitalist nation as the US,we all need to act like capitalists,doing a complete life-cycle-cost-analysis when planning on new or remodeled construction.
Cloverleafs will pay dividends for billions of years.
Conventional intersections will remain a cash liability for billions of years.
Students buy debt to finance future higher earnings a college degree can bring.
Taxpayers can buy short term debt to finance future low-cost driving only efficient infrastructure can bring.

[aerohead]

Originally Posted by Old Mechanic

If the incorporation of regenerative braking only requires a single component with relatively little added weight then most regenerative braking can be very helpful to overall efficiency.

I would prefer that option to waiting for the driving population to be reeducated and the road system redesigned. Around here it takes the traffic engineers 6 months to figure out the new light is totally out of sequence with the other 12 in a 3 mile stretch .

Lightweight vehicle with no exotic materials. Individual in wheel regenerating IVTs, with a small capacity accumulator and a .6 to 1 liter engine with electric supercharging.

Practically speaking, I don't see any significant improvement in the abilities of the driving population to become as situationally aware as those of us who drive for mileage. It would be nice to know what stage in the cycle the upcoming traffic lights are approaching, but around here that would not stop the blast and brake stupidity I see daily.

Maybe at some point we may actually change driving habits, but I doubt it in my lifetime. In the interim we should try to change the way the machine approaches the optimization of the fuel used for the distance travelled. In essence to incorporate hypermiling techniques into the vehicle itself instead of relying on the drivers actions to accomplish the same.

regards
Mech

In spirit,I agree with everything you mention.
What disturbs me,is that the infrastructure is like the elephant in the living room.
It has the potential to bankrupt.In a sense it already has.
Since the physics is well understood as well as construction technology,along with requiring automakers to increase CAFE standards to 35-mpg,we could begin to undo the mess we've made of our road system,which is robbing 10-mpg from every vehicle in urban traffic,something I'm not sure that automakers can compensate for.
My T-100 will do 39 mpg in the city with synchronization.Without it,we're looking at a little better than half of that.
That is highway robbery.

[aerohead]

Originally Posted by jamesqf

But of course that means you have to live in the flatlands. Try driving in the mountains without brakes :-)

Same applies to the "no left turn" plan. Works, sort of, if you only live & drive in an urban area. Not so swell if the 3 right turns you'd need to make would take you 20 miles or so.

The scenario is an urban environment.The cloverleaf is of proper radius that you blend onto it at constant velocity,as you emerge from it your heading 'left',at a constant velocity,getting twice the mpg your getting today in the city.No stops.No idling.No need for brakes until at your destination.

[user removed]

It's sad to see us discuss changing traffic patterns to fix what is wrong with cars.

The original topic was a "peoples car" along the lines of the Model T, the original VW, and many other examples such as the mid 70's Honda Civic with the cvcc engine.

By now most here know my preference for a hydraulic IVT drive located in the area normally reserved for friction brakes.

Massive reductions in power train components, the ability to change the load to maximise BSFC, or eliminate the necessity to modulate electric power delivery to a drive motor, as well as superb regenerative energy recovery percentages, compared to more complex designs.

Maybe one day people will look at the totality of the situation and see a simple solution. That's where I am today.

How much energy do you really need to be able to recover, and how much energy to you really need to apply to eliminate the small percentage of very wasteful periods in daily operation of your car.

Sure it would be great to redesign the roads to match the hypermilers skills perfectly. Sharp upgrades to pulse at max BSFC, with downgrades perfectly matched for engine off coasting.

Ever driven US 1 down the Florida keys? Try making a left hand turn on that road when traffic is heavy, and there are no lights to interrupt the bumper to bumper traffic at 50 MPH. I have watched people sit there for 15 minutes trying to make a left turn, when they could have turned right, made a U turn, and another right turn, in less than 1 minute.

How do you get great mileage in severe mountainous terrain. The lighter car has lower sectional density and would coast downhill at a lower terminal velocity. It would also require much less fuel to climb the same grade. Carrying around hundreds or pounds of batteries in steep terrain means much of your energy capacity is dedicated to increasing the elevation of the battery pack itself.

Having driven my Insight for over 20k miles now, I can see the logic Honda applied to the design of that unique car. I would just change the power train to a hydraulic IVT and the storage to a flywheel or accumulator. Either one would have about the same range capability as the original battery-electric motor combination, which was not very much. I would also reduce the engine size to 600 CC and add an electric supercharger.

I think what is not well understood, by some, is you really don't need much.

How many times do you have to accelerate rapidly to 60 MPH, or stop rapidly from the same speed. That's where your energy losses are the greatest and the storage really only needs to be capacitive to cover the normal stop and accelerate to speed cycle you hate when you get nailed by a poorly timed light.

I have seen objections to high density capacitive type recovery and application because it will not allow recovery of the available energy in severe elevation situations.

To me the best solution to driving in extreme grades is to minimize the vehicle weight, since this directly reduces the total power necessary to climb the grade, but it also means you have less weight behind the same drag forces, which reduces the top speed of the vehicle in a downhill coast.

Now, I know that may not be the best solution, and I would certainly like to hear from those who may have alternatives.

regards
Mech

[user removed]

Originally Posted by aerohead

The scenario is an urban environment.The cloverleaf is of proper radius that you blend onto it at constant velocity,as you emerge from it your heading 'left',at a constant velocity,getting twice the mpg your getting today in the city.No stops.No idling.No need for brakes until at your destination.

Aerohead:

I agree 100% with your criticism of road design.

I just believe that you can also eliminate the effects of bad road design, by incorporating high efficiency, simple, lightweight, virtually unlimited life expectancy, power train components to vehicles without extensive redesign.

In doing so you would make them less expensive, more reliable, and a lot more efficient.

Consider the most accomplished hypermiler on the planet. Their actions follow a totally predictable, and understandable pattern. The results are very predictable and repeatable.

Incorporate those techniques into the design of the vehicle itself, and you will have the "peoples car" of this century, instead of a tribute to the poor designs of the last century.

regards
Mech