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Let me describe a part of my commute to you. This part is right by home, and as such can pose a significant problem for me, as I just about have to hit it every day. I'd love to post a map of the roads in question, but I'm leery of including that sort of personal info in a random BBS post (no offense).

There's an intersection of two main traffic arteries, which are multi-lane roads. Call them A and C. The intersection is controlled by a light, and has dedicated left turn lanes and left turn arrows. In the direction I approach from work, I need to turn right there, and then a quick left onto a side street (M) at another light with a turn arrow and a turn lane. There is not enough room to the right of the right-hand traffic lane to squeeze by and turn right, so if there is more than one car at the light (which is usually the case, remember these are main arteries!) I must wait for the light to change and traffic to clear before I can go.

Then I get to stop at that next light (C and M), which is timed so that the turn arrow turns red just before the first cars from the previous intersection can get there. :( So I have to wait for the (long) cycle of the light before I can make my left turn.

I do have options, though. I can cut off of A and turn right a little early (on W), making my way through back roads to the intersection of M and C. I can go straight through that and home, instead of having to wait through two lights. However, that intersection is set up so that you cannot see the light until you are nearly on top of it (a sharp turn and trees block it) so it can be quite hard to anticipate. I therefore find myself stuck frequently at that light.

I could also go a couple of blocks past the big intersection, and make a right turn onto a different side street (call it L), then come back up along M to the turn-off to my house. Alternately, I could take W but go futher to the right before cutting over to C, where I would have to turn left at another dedicated turn arrow. I would then turn right onto M to get home.

[As an aside, things are timed much better for me when I leave; I can do the right turn first for one thing, and I have enough drive time to recharge the battery after starting the car a couple of times.]


So, how can I handle this to minimize my fuel use? Alternately, how can I maximize my MPG? (I recognize those can be at odds, and I am not completely opposed to "running up the numbers" in a small way. ;) ) I really hate having to wait at the M and C light in any case, particularly when it is difficult to time effectively. Couple that with the fact that I sometimes arrive after dark so that headlights are necessary, and I feel that I have to sit there with my engine idling, wasting fuel.

The remaining part of my commute is, depending on my mood, either an acceleration away from the M and C intersection to 25 MPH, then a turn and a glide to my parking spot, or a pulse to 15, then make the turn to my house, then a pulse to 10-15 MPH after the turn and coast to the spot. When I think my battery can handle it (e.g., no lights needed!!) I make the glide(s) with the engine off. Note that this gives my charging system just about zero time to replenish the power used to crank the starter at the M and C intersection--and I am at least a little nervous about my battery's state-of-charge (and state of health, but that's another issue).

Any ideas how I can improve this?

-soD

I'm thoroughly confused.

I had a similar issue when trying to decide my commute. The aera around me has a fairly dense population, and most of the road are at least 3 lanes.

I found when choosing me new route I would try to minimize the total amount of stops I had to make. Accelerating uses up the most fuel, especially going up-hill. Making right hand turns are better than lefts sinc eyou generally don't have to wait at a light. As for anticipating I find assuming the light is going to be red works when I can't see the light. Granted you run the chance of the light changing on you as your cresting the hill/rounding the turn. If you're already deccelerating it won't make much difference. If the light is green you can simply roll onto the gas.

Ultimately it's hard to say what works best from afar. Some trial and error is going to be needed. If you have a scangauge this should be pretty easy. If not, try a tank to tank comparison of the routes. The key is being consistent with the latter method.

Good luck to you!

Sorry, Dixie, I was trying to describe something that would probably best be done with a picture... I will try to make one at some point, but I do not have the time right now.

Biker, my 1990 is not SG II capable. And I'm not nearly consistent enough over the course of a tank to see the difference in the route.

-soD

I want to help, but it's hard to follow all of that. A picture would help a lot.

Here's what I'd do: Google maps, Printscreen, MSPaint, paste, save, upload.

Um, yeah. See the point in my first post about "leery of posting personal information". I'll try to make a more abstract map when I can...

-soD

OK, here we go. A very crude stick-figure type drawing of the commute section I'm talking about:

http://members.rennlist.org/damp_dave/commute.jpg

My current route is to follow the blue arrows. The very thick lines are the two major roads.

Note that all the shoptlights shown are pretty long ones. After that light in the middle of the diagram, I pulse for somewhere around 10 seconds total before I am parked.

So, does that clear things up at all?

-soD