Friday, June 5, 2009 upcoming changes is less than two weeks old, and I've spent that time on my bike, did a Memphis - Blue Ridge - Montreal - Toront0 - Chicago loop, and stopped to talk to bikers and web experts along the way. The result is a list of new features for the site, which will be added in coming weeks.

We'll have new sections on adverse weather, restricted-access freeway riding strategy, a calculator for stopping time and distance and a new visual treatment for the risk hierarchy. We'll be adding new links and also RSS feeds and a mailing list for bike safety updates so you can use our content on your bike site or forum easily, providing updated seasonal and topical motorcycle safety content for your site users. We have a new feature in the works so you can judge for yourself the effect of using daytime high beam, modulator and running lights to a bike to improve conspicuity. These and a whole rack of improvements and visual aids.

Relating to the conspicuity page, I also found that many truck stops are selling clear, amber and red three super-LED flat-mount lights as truck marker lights, at about a quarter the price of the police super-LED flashers I quoted in the page. I think these might be a good option for bike conspicuity and we'll be experimenting with some of these and reporting the results.

We're also getting some advice on improving the site design from my friend Robert Hamilton and you'll be having a smoother and slicker user experience as we develop the site.


Sunday, May 24, 2009

2-second rule not enough for highway speeds

My friend Hamayar, who hails from Wales, sent me this link, from the UK Survival Skills site. The site is pretty cool, although some of the articles need translation to driving on the right. The referenced article makes the point that the two-second rule provides a following distance in which the bike sometimes can't stop in time to avoid a vehicle stopping in front. His calculation is basically that the two second rule is insufficient at speeds of 60 mph and above, probably because the distance covered during reaction time is greater at these speeds.
Food for thought, epsecially for group riders on the highway.
My take is that the calculations aren't conservative enough. He uses 0.9 G of braking force for the motorcycle braking force, while the Quebec Promocycle Foundation did a study that found more like 0.75G for a bike without ABS but an experienced and skilled rider. The Quebec site has more on rider reaction time also, which makes the half second response time look a bit skimpy. The average seems to be consistently a bit over the half-second, and is actually worse for women. The average reaction time looks more like 5.3 seconds, and a large number of the braking intervals sampled were longer than this average.
The Quebec study suggests that both the assumptions the Survival Skills author used were skewed toeards underestimating the problem.
The lesson is clear. The two second rule is an absolute minimum at speeds up to 45 MPH - or maybe less - and seems to be less adequate at highway speeds or greater.
Has anyone got a calculator who can apply the Quebec numbers to the Survival Skills computations? I bet that would be a scary set of numbers.
In the meantime, we should probably rethink our following distance calculations for highway speeds, and add a liberal (or conservative) dose of extra following time to the two-second rule. For group riders and lead riders, perhaps something to mention at the next safety briefing. Looks like inexperienced riders might want to add even more time cushion.
In the meantime, y'all enjoy the Promocycle and Survival Skills websites.

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Saturday, May 23, 2009

Welcome to ET's Bike Safer Blog

Bike Safer and its blog is up. Welcome and feel free to post your comments, additional info, crash stories, handy links, and errata.
I've been working on this for six weeks, today some beer, and celebrate with Special ED and friends. Tomorrow I am off on my planned ride to Montreal, which has been delayed by HTML. I won't have my laptop with Dreamweaver, so it is the blog for now.