1. Attachments are working again! Check out this thread for more details and to report any other bugs.

55 MPH

Discussion in 'Gen 2 Prius Fuel Economy' started by DaveinOlyWA, May 4, 2005.

?
  1. yes!! now i will get 60 mpg in my Prius

    0 vote(s)
    0.0%
  2. no... im afraid of being run over...

    0 vote(s)
    0.0%
  1. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

    Joined:
    Apr 13, 2004
    15,140
    611
    0
    Location:
    South Puget Sound, WA
    Vehicle:
    2013 Nissan LEAF
    Model:
    Persona
    a recent article in the NY Times discusses the possibility of lowering the national speed limit to 55 mph again as the easiest way to lower our thirst for gas.

    the last time the nation went to the 55 mph speed limit was the only time in our history that our comsumption of oil had dropped. that along with the CAFE mandates helped us level off or reduce our oil needs for nearly 10 years. but today, CAFE is not likely to happen because of too much opposition. the speed limit the president can institute much easier

    55 MPH
     
  2. galaxee

    galaxee mostly benevolent

    Joined:
    Mar 14, 2005
    9,810
    464
    0
    Location:
    MD
    Vehicle:
    2005 Prius
    you know people are still going to go 80mph down the highway if they can. you can't alter free will by altering laws. all you can do that way is make it more costly to do what you like.

    i don't think it will work, personally. if everyone actually did it, yes, it probably would. but people today are all snobs it seems and do whatever they want. sigh...
     
  3. gschoen

    gschoen Member

    Joined:
    May 9, 2004
    343
    3
    0
    Location:
    Chicago/Wrigleyville
    Vehicle:
    2014 Prius Plug-in
    Model:
    Plug-in Base
    Many highways I drive on (urban areas ) limits are 55 or even 45 inside Chicago, but at 75MPH I don't qualify for the left lane club.

    Speed limits should be based on what the road design can safely support. Artifically setting limits lower than designed causes problems of its own.
     
  4. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

    Joined:
    Apr 13, 2004
    15,140
    611
    0
    Location:
    South Puget Sound, WA
    Vehicle:
    2013 Nissan LEAF
    Model:
    Persona
    actually around here many are still law abiding. the only thing is that now where most of the speed limits in urban areas are 60 mph... speeds up to 70 seem to be allowed.

    dropping the speed limit to 55 mph may in effect lower the permissible to 65 mph. that would save a large amount of gasoline. studies showed that even with lax enforcement of the 55 mph speed limit from 1974 to 1984 (the length of the study) that it still saved 2.5 billion gals of gas a year. that is a months supply.

    the problem here is that 7 miles south of here the speed limit changes to 70 mph all the way to Oregon. i think that is too high and the spate of accidents with deaths confirms this. it seems that having a speed limit of 70 just makes people think they can drive 80 and that is a problem
     
  5. hdrygas

    hdrygas New Member

    Joined:
    May 22, 2004
    3,650
    6
    0
    Location:
    Olympia Wa
    Vehicle:
    2004 Prius
    Look at states like Montana where 70 mph is the day time speed limit on two lane secondary roads, and given the distances people drive there to get groceries or medical care it may well be justified. As fuel prices rise people in states like that are in trouble. We have eliminated trains that they might have used in the past. There are a lot of people in remote areas that will suffer as prices rise. Of course they largely produce the food that people in more densely populated areas eat. Not good.
     
  6. Ray Moore

    Ray Moore Active Member

    Joined:
    Mar 28, 2004
    857
    52
    0
    Location:
    Texas Hill Country
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    This would work to lower the price of gasoline to 1.50 within two months. People would go back to driving 62 mph and would seldom drive 80 mph due to that being the limit for a reckless driving charge in many states.(25 mph over) Once the price of gas dropped, and it would be fairly rapid, most would wonder why we were inconvenienced in this way. The price drop would begin before the measure was even instituted. Once the measure was signed into law, the futures market would plummet. Traffic fatalities would also fall dramatically again.

    Large states with thousands of miles of highway would be the harshest opponents, just like last time. It would only happen with strong backing from Bush and that kind of leadership is unlikely from this administration.

    I would personally prefer 60 mph as the national limit, which would in effect be a 65 mph limit due to enforcement procedures.

    By the way, the US consumption has fallen from the previous year seven times since 1981, including some rather recent years. World consumption has done that three times since 1981. It's easy information to find. The most powerful mechanism for lowering energy demand is economic recession. Each recession leads to a drop in demand. Each drop in demand leads to a drop in fuel prices. Each drop in fuel prices helps economic recovery and so on and so on. Four weeks ago the sharp drop in oil prices was sparked by a downward revision in economic forecasts by the EU from 2% growth to 1.6%. Just the possible downward movement in their economy caused the price of oil to drop over 2 dollars in a day. Bush meeting with the Saudis had less of an effect.
     
  7. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

    Joined:
    Apr 13, 2004
    15,140
    611
    0
    Location:
    South Puget Sound, WA
    Vehicle:
    2013 Nissan LEAF
    Model:
    Persona
    maybe a regional speed limit law is more in line then. only on long barren stretches of road should it be 70 mph. i never could understand why I-5 south of Tumwater is 70 mph. however, i am in favor of keeping I-90 at 70 mph east of Issaquah at least until it hits some civilization (in about 300 miles)
     
  8. Tideland Prius

    Tideland Prius Moderator of the North
    Staff Member

    Joined:
    Oct 2, 2004
    44,767
    16,016
    41
    Location:
    Canada
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    Most of the hwy speed limits here are at 80-90km/h with the occasional 100km/h (110s are usually on outskirts such as Hwy 2 from Edmonton to Calgary). Most do travel around 90-100km/h (10 over the speed limit seems to be the max tolerance)
     
  9. GAGendel

    GAGendel Junior Member

    Joined:
    May 3, 2005
    59
    0
    0
    Location:
    New Jersey
    I never (well almost never) exceed 5 miles over the 65 MPH speed postings. Here in NJ that can almost get you killed as they blow past you at 80-90 MPH. It's like I'm standing still.

    I oppose a reduction in the speed limit for several reasons:

    1) As previously mentioned, people use this as the lower limit anyway around here.

    2) It would add 40 minutes to an already long drive when visiting my son in college.

    3) Big brother easily gets out of control and sometimes needs to be kept in check. Point in case is the NAV/Bluetooth lockout. I don't mind the hands free cellphone laws, but this prevents me from utilizing it.
     
  10. Venturer

    Venturer New Member

    Joined:
    Apr 15, 2005
    79
    0
    0
    Maybe I'm getting old, but I find driving slower to be more relaxing. My diesel motorhome could run 75 all day long, but I run 55-60 so I can enjoy the sites. I can still cover 600+ miles in a day. I drive on the interstate about 20 miles to my business in my Avalanche at about 60mph or less. I don't mind being passed by everyone else. The fact that I get better mileage than other people with the same vehicle is the only reward I need. Now if my wife would let me take the Prius, I could really feel good, but she won't let it go. She claims that it is hers and won't share. I looked at the screen last night and it said 60.1 mpg. Now she's thinking of places to spend all the money she is saving.

    Doug
     
  11. mikepaul

    mikepaul Senior Member

    Joined:
    Dec 2, 2003
    1,763
    6
    0
    Location:
    Columbia, SC
    Vehicle:
    2004 Prius
    70MPH roads do make my annual trek to the family reunion less tiresome, and when I toed the speed limit last year I got great MPGs but didn't know why I was so far behind, until I remembered that I used to go +5 in all speed zones to shave an hour off the 12+ hour trip.

    To cut back to 55MPH at the fastest would probably leave me doing a lot of 60, which wouldn't hurt my wallet but would leave me on the road a lot longer, making me more tired and accident prone.

    So, when gas is unavailable, THEN restrict speed to conserve. When it's just expensive, let people spend their money as they wish...
     
  12. Canuck

    Canuck Member

    Joined:
    Aug 16, 2004
    605
    2
    0
    Location:
    Vancouver Island,BC,Canada
    Vehicle:
    2011 Prius
    Model:
    Three
    Here on Vancouver Island we have 30km/h (18.7 mph) in school zones, usually 50km/h (30mph) in towns and cities, mostly 80km/h on highways except on newer, well designed, median divided where 90km/h (56 mph) or even 100km/h (62mph) is posted. What speed some folks drive at is another matter..
    Can't really say all this gives us much better consumption figures or reduced accident rates.... in the six months we've had our Prius we have averaged in the 11 fill ups 52.63 mpg (CAN) 42.68 mpg (US).
     
  13. skruse

    skruse Senior Member

    Joined:
    Apr 6, 2004
    1,454
    97
    0
    Location:
    Coloma CA - Sierra Nevada
    Vehicle:
    2007 Prius
    Model:
    II
    I concur, set the limit at 100 kmph (60 mph). Despite an increase in fuel prices, I am amazed daily at those that "fly" by on the right and those that weave in and out of all lanes in an impatient effort to get ahead.

    Tractor-trailer lane and speed controls seem to be ignored and the mix of passenger vehicles, pickups and tractor trailers sometimes makes for high tension driving. I look in awe at the significant mass and kinetic energy embodied in a tractor trailer traveling well above the speed limit. Diesel is now the same price as gasoline in many areas, so high speed tractor trailers are not cheaper to operate.
     
  14. KCPrius

    KCPrius Member

    Joined:
    Nov 26, 2004
    133
    1
    0
    Location:
    Overland Park, KS
    I wouldn't want the limits reduced. While it might get me 60 mpg, I am perfectly happy getting in the high 40's while driving 75 mph. For those on the west coast - you've at least got something to look at and enjoy the view while driving 55. I invite you to drive from Kansas City to Denver, and see how long you will stay at 55 - especially once you get past the Kansas flinthills. After that....miles and miles of.....flatness. And when you see that Denver is still 500 miles away - your foot unconsciously presses harder on the accelerator...until you are cruising 80 or more. Shoot...they build an occasional curve in the interstate - look at what I-70 does between Oakley and Colby, Kansas...that's your reminder that you're almost in Colorado.
     
  15. micheal

    micheal I feel pretty, oh so pretty.

    Joined:
    Apr 14, 2005
    842
    2
    0
    Location:
    Lubbock, TX
    Vehicle:
    2004 Prius
    I think it would be a good idea to lower the speed limit I don't see an across the board 55mph as being feasible. It seems like there could be some compromise though to slow down in town freeways, but pretty much leave some of the wide-open spaces alone at 70 or 75 (like Wyoming/Kansas, etc.)
     
  16. jayman

    jayman Senior Member

    Joined:
    Oct 21, 2004
    13,439
    639
    0
    Location:
    Winnipeg Manitoba
    Vehicle:
    2004 Prius
    <div class='quotetop'>QUOTE(KCPrius\";p=\"87447)</div>
    That's what the Cruise Control is for.

    Personally, I would like to see highway travel as tightly restricted as airspace travel, where altitude and speed limits are strictly observed and enforced.

    I'm all in favor of reducing the speed limit to 55 MPH or 90 km/h. When this was done in the 70's, both our fuel use AND our highway fatality/injury rate dropped.

    The fatality/injury rate reduction may also have had to do with more enforcement of seatbelts and drunk driving, so there are many other effects to consider.

    Unless you believe in Perpetual Motion and the Tooth Fairy, you should be able to accept that the energy managed in a crash increases beyond linear with changes to speed. In particular, the Kinetic Energy is equal to 1/2 the mass multiplied by the velocity SQUARED.

    Converting from MPH to metres per second, 55 MPH is 24.587 m/s and 75 MPH is 33.528 m/s. Increasing the speed limit from 55 to 75 is an increase of about 36%.

    Squaring the velocity of 24.587 m/s is about 604.52.

    Squaring the velocity of 33.528 m/s is about 1124.13. An 86% increase.

    Things like occupant protection systems, brakes, and steering are all less effective the faster you drive. And for larger vehicles that have high frontal areas, faster speed limits result in a much bigger hit to fuel economy than to our Prius.

    An interesting study was done by the Iowa Department Of Transportation:

    http://www.dot.state.ia.us/pdf_files/2002s...ate_summary.pdf

    At a certain point, you have to ask if the travel time "savings" is more important than the obvious and proven benefit of reduced fatalities, injuries, and fuel consumption.
    Of course, you have the "right" to drive as fast as you want. I want the "right" to refuse to pay one penny for the increased health care costs and financial costs.
     
  17. KCPrius

    KCPrius Member

    Joined:
    Nov 26, 2004
    133
    1
    0
    Location:
    Overland Park, KS
    Jayman - Yes, that's what cruise control is for. But when you are set at 55...and you se a sign that says "Denver 500 miles" and drive for about an hour and see another sign that says "Denver 450 miles", after a while it starts to taunt you. In fact, I'd venture to say that on long flat stretches, a higher speed is condusive to FEWER accidents, as it's less likely to cause boredom/fatigue. If anything, I would prefer a setup like Germany - let conditions dictate speed on open areas of the road, but as you approach urban areas, set limits, and strictly enforce them.

    Also, my theory is that higher speed limits don't increase accidents or fatalities. I believe that people will tend to drive at a "comfortable rate", regardless of the speed limit sign (Montana used to post a "limit" of "reasonable and proper"). When they go over the speed limit, the focus begins to shift from paying attention to the road to looking out for speed traps.
     
  18. pkjohna

    pkjohna Member

    Joined:
    Jan 20, 2004
    228
    1
    0
    Location:
    Manassas, VA
    Vehicle:
    2012 Prius
    Model:
    Four
    I say get rid of the national limit altogether -- let the states determine those regulations.

    I'd rather see higher speed limits on many rural interstates along with stricter enforcement. There are many parts of the country where the roads are sparsely traveled, the scenery is flat as a pancake. In those cases the visibility is measured in miles and you're not going to run into any surprises that overwhelm your reflexes even if you're going 100 let along 70. Also, it's just absurd to have to guess at the current "whisper number" for the allowable speed based on the current mood of the local gendarmes. We certainly have the technology to make speed enforcement more consistent and less labor intensive and such improvements could be easily paid for by the high number of fines incurred until folks get the message that they're not getting away with anything. For that matter, we have the technology to enforce safe following distances so when traffic doesn't allow safe driving at higher speeds the cars could be slowed down automatically.

    On my daily commute I usually set my cruise control at about 62 (or 5-7 miles over the posted speed except in urban areas where I stay at the posted speed or below) but when I'm on vacation it's worth a couple of bucks in gas to get where I'm going without spending quite as much time on the road.

    I do think trucks and other heavy loads in particular need some sort of automated enforcement of reasonable speeds for safety's sake if not for the economics.
     
  19. Electric Barbarella

    Electric Barbarella New Member

    Joined:
    Apr 21, 2005
    11
    0
    0
    Location:
    Lawrence, MA
    Take the speed limits away, and put up toll booths or rotary traffic patterns every 20 miles.

    Personally, I hate the signs in New York that say STATE SPEED LIMIT 55. Build a bridge and get over it.
     
  20. 200Volts

    200Volts Member

    Joined:
    Nov 19, 2004
    429
    43
    1
    Location:
    Northern CA
    Vehicle:
    2006 Prius
    Model:
    N/A
    If you want to save gas on a national level just find a way to enforce tire pressures (like the new mandatory monitoring devices coming out soon). Keeping everyone's tires inflated will save about twice as much gas as lowering the speed limit.

    I drive 50k miles a year. Slowing down 15 mph would cost me another 200 hours/year stuck in my car. At $100/hr billable rate that COSTS ME $20,000 per year. My gas savings from 50mpg to 55 mpg would save me 90 gallons/year or $250.00 Any other questions?