I have two videocameras fitted to my bicycle - one on the handlebars facing forwards, and one on the pannier rack facing backwards.


Date Summary Video Narrative Update
2007-9-15 Crash 7Mb theora; 6Mb mpeg1 one entry
2007-9-10 Tailgating by taxi SF07 DFK 7Mb theora; 7Mb mpeg1 one entry
2007-9-10 Cut up by taxi LV04 NZT 11Mb theora; 10Mb mpeg1 one entry
2007-9-10 Tailgating by and collision with N99 JHC 24Mb theora; 21Mb mpeg1 one entry
2007-9-10 Tailgating by M843 GFL on Mill Road bridge 9Mb theora; 7Mb mpeg1 one entry
2007-8-29 Considerate drivers in Stowmarket 12Mb theora; 11Mb mpeg1 one entry
2007-8-22 EA04 UXJ cuts us up, driver is abusive 11Mb theora; 10Mb mpeg1 one entry
2007-8-13 Tailgating and close passing by taxi FH51 BJU 6Mb theora; 6Mb mpeg1 one entry
2007-8-1 Tailgating by L611 JEG 11Mb theora; 10Mb mpeg1 one entry
2007-8-1 Narrow bike lanes on East Road 5Mb theora; 5Mb mpeg1 one entry
2007-7-30 KN51 TXU pulls out forcing me to swerve and brake 10Mb theora; 9Mb mpeg1 2 entries 2007-8-1 Reported to police
2007-7-30 Close passing by taxi no.86 OV04 CLJ 3Mb theora; 3Mb mpeg1 one entry
2007-7-30 Dooring zone bike lane considered harmful 4Mb theora; 3Mb mpeg1 2 entries 2007-7-31 References to CCyC comments when lane painted
2007-7-3 Bus and bike lanes used by Smart car & G424 OFL 3Mb theora; 3Mb mpeg1 one entry
2007-7-2 POB fails to keep left; dippy pedestrians 4Mb theora; 4Mb mpeg1 one entry
2007-7-2 T809 DLW pulls out without looking 10Mb theora; 9Mb mpeg1 one entry
2007-7-2 Barging in a residential street 4Mb theora; 3Mb mpeg1 one entry
2007-7-1 M533 TPU pulls out without looking 5Mb theora; 5Mb mpeg1 one entry
2007-6-28 Barging and intimidation by X584 EGF 5Mb theora; 5Mb mpeg1 one entry
2007-6-11 Pavement parking 11Mb theora; 8Mb mpeg1 one entry
2007-6-11 Close passing by SC56 XVZ 4Mb theora; 4Mb mpeg1 3 entries 2007-6-13 Police will use as `intelligence'
2007-5-22 Dangerous passing, cycle lane violation by KJ03 GNX 39Mb theora; 38Mb mpeg1 one entry
2007-5-21 Tailgating by taxi PN56 TXX 26Mb theora; 24Mb mpeg1 3 entries 2007-5-29 Driver given `words of advice'
2007-5-21 Undertaking in bus lane by K326 DRF 5Mb theora; 5Mb mpeg1 one entry
2007-4-30 Close passing by H748 FMJ, threats 29Mb theora; 29Mb mpeg1 3 entries 2007-4-30 Police visited, took videos
2007-4-30 Post van BU04 WKH on pavement, bike lane one entry
2007-4-30 POB Mitcham's Corner wrong way 3Mb theora; 3Mb mpeg1 one entry
2007-4-30 Haart's CE54 UKF on pavement, bike lane 8Mb theora; 8Mb mpeg1 one entry
2007-4-29 Close passing at speed by L434 XFW 5Mb theora; 5Mb mpeg1 2 entries 2007-4-29 Reported to police
2007-4-27 Traffic island, KU51 RXF cuts me up 15Mb theora; 13Mb mpeg1 one entry

Trouble viewing the videos? Wikipedia has useful instructions. (Wikipedia page `Media help (Ogg)' retrieved Mon, 30 Apr 2007 15:19:28 +0100.)

Distance calibration

It can be difficult to judge distances in the videos. To help with this, I have a video which contains shots of a number plate at various measured distances:

Calibration video giving distances in metres as 3.6Mb theora; 4Mb mpeg1.

Photos and demo

Photos and videos are available to give you an idea of the setup.

The photos show the cameras attached to the bike.

The two videos (the .ogg files) show my journey from Gilbert Road to the Parker's Piece corner at the end of Regent Terrace, in the light, and back again, in the dark. Nothing very unusual happens in these videos, so don't bother watching them for the excitement.


As you can see, the camera performs reasonably well and I think it will be able to perform its main function of providing evidence in cases of road traffic incidents. However, there are some limitations:

The chief difficulty is that the field of view is rather narrow. Many events of interest may occur outside it, especially hazards from the sides. It also gives the impression that things (particularly, vehicles) are much closer than they really are.

The strange jelly-like effect (most visible on the front camera when going over bumps) appears to be caused by the camera not capturing the whole frame at a single instant: so, as the camera moves up or down, objects are vertically squashed or stretched. I was able to reduce this problem from initially unmanageable distortion by greatly increasing the rigidity of the front camera mounting.

At night the imagery is very poor in all but the best-lit streets and my own front light is evidently not strong enough to help this much.

The audio track is nearly useless. In the example videos there are a couple of occasions where I shout warnings to other road users, which are barely audible let alone intelligible. In contrast, brake squeal and road noise are very loud.

Using the camera to record registration plate numbers will be difficult unless the lighting conditions are good and the distances small, and because the audio track is so useless merely calling out the number won't help. I'll have to keep to pencil and paper.

Technical details

The cameras are Oregon Scientific ATC-2000s. They each record up to 1h of 30fps 640x480 video onto the 2GB SD cards I use. There is a soundtrack too but it isn't really useable for most purposes.

The cameras produce .avi files containing a pile of individual .jpeg frames and an uncompressed 8-bit 8khz u-law soundtrack. I have a script which postprocesses a pair of .avi's into a single ~220kby/s .ogg (vorbis audio plus theora video) stream.

The script (written in bash) uses:

This software is available for download. It is in source form only and not very well documented so you will need to be a reasonably competent user of the Unix command line to make use of it. The dependencies are all satisfiable using packages only from Debian etch main.

Ian Jackson /

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