Today’s Headlines

  • RTA Releases Ventra Audit, Says CTA Has Seen Little Financial Impact (Tribune, Sun-Times)
  • Interim RTA Director Appointed in Wake of Harassment Allegations (Tribune, Herald)
  • 4 Windy City Rollers Injured by Driver Evading Police (RedEye)
  • More Than $10K Raised for Family of Hector Avalos (RedEye)
  • Trucker Sentenced to 4 Years for Fatal 2009 DUI (Tribune)
  • Lessons for Chicago From Japan’s Transportation Network (Gapers Block)
  • National Motorists Association Want Tollway Speed Limits Raised to 70 (Expired Meter)
  • Clearing Roads From Early Snows Is Taking Toll on City Budget (Tribune)
  • CTA Rail Car Sells for $13K in Auction (RedEye)
  • Diary of a Winter Bike Commuter (Ding Ding)

Get national headlines at Streetsblog Capitol Hill

  • Katja

    Thanks for the signal boost on the Windy City Rollers article. They’re all great women, and the crash was really terrible.

  • Sure thing. Thoughts are with the crash survivors. Let us know if any fundraisers are planned and we’ll help get the word out.

  • Fred

    If the goal of the interstate network is to safely, quickly and efficiently move goods and people great distances, then its hard to deny that 70mph speed limits make sense outside of “commuter zones”.

  • CL

    I just drove 850 miles across the country for the holidays. All of the states I drove through have moved to 70, and it was perfect on almost every interstate. There were a few zones where the limit was 60 or 65, but then it went back up to 70 — Illinois could do the same on stretches where the data show 70 is too fast.

    70 actually felt too fast on a few stretches through the mountains, but I noticed that most people (me included) adjusted and drove slower through those stretches. Otherwise, 70 felt safe and efficient — I didn’t have that frustrated feeling of driving “too slow” on a 15 hour trip. It was great.

  • Yes, but in areas with 3-5 exit/entrance ramps per mile and heavier traffic most of the day, even 55 is often far too high for safety.

  • Fred

    Are there places “with 3-5 exit/entrance ramps per mile and heavier traffic most of the day” outside of commuter zones?

  • BlueFairlane

    Similar to CL, I just drove across country to and from Colorado, the kind of trip I make often, through states with speed limits at 70 or 75. I’ve never seen a problem with the higher speed limits in these states. Traffic dynamics seem to mirror what I see when I drive across downstate Illinois, in fact, only the scenery passes faster. The only state with a higher speed limit where I’ve ever observed a problem, I think, is Indiana, which has a 70 mph limit. The problem there, though, is that they maintain a different speed limit for cars than for semi trucks. These different limits often cause a lot of bunching as slow-moving trucks try to pass slower-moving trucks, and cars group up behind them. I would hope Illinois wouldn’t try pulling something like that.

  • I was just being more specific and quantifiable about it. :-> Since ‘commuter zones’ is a term just begging to be argued with … especially by people who want the 294 between O’Hare and the 55 to be 75MPH throughout, which is insane by my lights. 3-5 exits/mi may not be the right number, but I think it’s the right kind of metric.

  • The problem with trucks is that the weight is high enough that small increases in speed can make massive differences in wear-and-tear on the roads, meaning much more frequent maintainance.

  • Fred

    Well I just made up the term, so debating its meaning is fair and reasonable.

    Commuter Zone speed limits really should be real-time demand based. Why shouldn’t I be able to drive 75 on 294 between O’Hare and 55 at 3am on Tuesday when conditions permit? This is what is already happening on the tollways. Certainly no one is going faster than 30mph during rush hour, even if you were to abolish the speed limit.

    I might even be convincing myself that explicit speed limits should be abolished on interstates in the commuter zone. That wouldn’t mean that anyone can drive as fast as they want, it just means that the outliers should be ticketed. If all traffic is going 80, there’s no reason to write tickets. If traffic is going 80, and one jerk is doing 95, that person should get a ticket. Same thing during rush hour. If traffic is generally moving at 30 and some jerk is doing 55, that person should be ticketed. Its the deltas that are dangerous, not the individual speeds.

  • BlueFairlane

    This is one of those statements that begs to be quantified. How much difference in wear-and-tear and maintenance costs would raising the speed limit 5 mph for trucks in Indiana make? Is there a quantifiable difference in the maintenance costs for Indiana and, say, Kentucky, which has a 70 mph speed limit for all vehicles? Does the difference in maintenance cost outweigh the safety and traffic flow issues created by maintaining separate speed limits?

    My guess is the answer is no, which is why Indiana is one of only a few states that maintain different speed limits on the same roads. Do you have evidence to suggest my guess is wrong?

  • I don’t personally have that data, but I bet it’s readily researchable in this Internet Age. :->

  • BlueFairlane

    Yeah … I don’t see much need to do research to prove your point. Thanks anyway.

  • I didn’t mean to make a point; I have no particular pig in this race. I don’t really have the time this week to dig into detailed urban-planning and traffic-engineer background sites, because today and tomorrow are the last two days I have to prep to take a 4-year-old out of town for two weeks. But far be it from me to put that project on you, either, necessarily; I just think there may be some (possibly flawed or misunderstood by the rulemakers) factual basis underlying the admittedly inconvenient regulations upon the movements of semis on rural interstate stretches.

  • BlueFairlane

    So, then, it sounds like we can both just agree that your original reply to my comment had no basis in fact. Very well.

  • Jim Mitchell

    Hey, guys … the issue is being investigated: http://www.asce.org/cemagazine/Article.aspx?id=23622326470

    Come back next spring for results of the studies. The article prefaces its discussion by noting that there doesn’t really seem to be a very good (or at least not a scientifically based) reason for differential speed limits.

    The studies described in the linked article are going to look at several factors that could/should/ought to influence lawmaker decisions, including the “wear and tear”/maintenance cost issue you have both noted.

  • BlueFairlane

    I found that one and plan on looking for the study when it comes out.

    Looking through the internet, you can find a smattering of studies that lean mildly either way in terms of safety or traffic flow. I haven’t seen anything that suggests an effect on roadwear, most particularly as it applies specifically to trucks. I found a long, nordic pdf (http://www.nvfnorden.org/lisalib/getfile.aspx?itemid=261) that studies other factors related to trucks and road wear, though this seemed to focus on issues of weight distribution. Speed didn’t play a factor. I suspect that’s just a red herring. I can’t think of any reason why speed differences would play a role.

  • CL

    Yes! That’s the exact problem with Indiana. You very frequently encounter long lines of cars stuck behind a truck that is very slowly passing other trucks. Then you get to Ohio, where it’s 70 for everyone, and it’s so much better.