In absolute terms - I love Copenhagen

"Bicycle Tracks and Lanes: a Before-After Study"by Søren Underlien Jensen, Paper, January 2008 on first sight is saying that cycle tracks and lanes are unsafe. But is it? I - intrigued - had a look at the paper.

Let's have a look at absolute numbers first. As with any study, that's the raw data to you and I. Absolute numbers are the totally unmitigated figures, not adjusted for context of traffic volume or distance travelled. Using absolute numbers without considering the surrounding circumstances can lead to hilarities like this one. Remember this? Once upon a time there was Norman Baker who had a 'cycle' chum Mike Penning who proudly pronounced that "The Netherlands could learn from UK on cycle safety" covered by bikebiz, roadcc and guardian.

Little Mikey was looking at total cycle deaths (UK 100 vs NL 300) rather than contextualising it with the number of people on bikes and/or the distance cycled. This silly man was actually saying "Cycling in the UK is safe (there aren't any cyclists)" or "UK is a very safe country for bear attacks and mosquito bites".

Absolute figures are important for before-after comparisons as total collisions numbers may actually go up due to increase in ridership and journeys.

Anyways, back to Denmark.

So.

The absolute figures from Jensen study are as follows ref. Tables 3

		Observed	Observed
	Category	BEFORE	AFTER	Reduction
Crash	All	2,987	2,911	3%
	Injury	1,313	875	33%
	Property damage only	1,674	2,036	-22%
Injury	All	1,476	937	37%
	Fatal	25	22	12%
	Severe	757	665	12%
	Minor	694	250	64%
		Observed	Observed
	Category	BEFORE	AFTER	Reduction
Intersection	All crashes	2,010	2,171	-8%
	All injury	938	636	32%
Links	All crashes	977	740	24%
	All injury	538	301	44%
		Observed	Observed
	Category	BEFORE	AFTER	Reduction
Pedestrians, all injuries	Total	469	315	33%
	At intersections	267	197	26%
	At links	202	118	42%
Bicyclists and moped riders, all injuries	Total	574	406	29%
	At intersections	353	285	19%
	At links	221	121	45%
Motorists, all injuries	Total	433	216	50%
	At intersections	318	154	52%
	At links	115	62	46%

The numbers of slight concern would be the negative reductions (ie increases) in the right-hand column. I say 'slight' because injuries are down and only property got damaged. Now... this is where we should not forget that these absolute terms haven't even been adjusted for the increase in cycling which was a respectable

• "20% increase in bicycle & moped traffic and a 10% decrease in motor traffic" on tracks
• "5% increase in bicycle & moped traffic and a 1% decrease in motor traffic" on lanes

So how is this study used to "prove" cycle infrastructure is dangerous? Well. The Jensen study tested a prediction model (these fancy algorithms listed on early pages in the study) which already factored in a reduction in collisions. And the prediction model predicted lower reductions than were achieved in reality. That's it.

My advice, be skeptical when someone quotes yet another study that "proves" that cycle facilities are dangerous. First look at totals, then check whether adjustments for increase in bike traffic, distinction between collision or injury categories (such as fatalities, major, minor, near-hits) have been made.

And yes, it's important to get the design of cycle tracks and lanes right too. Remember: existence of real cycleways in the UK is few and far between. What the Jensen study is talking about are proper pedal routes, not the substandard sh*te that cyclists - condemned to second-class citizenship by the UK authorities - get here.