Bridge height and weight app

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Terry

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May 13, 2010, 7:43:15 AM5/13/10
to Warwickshire Open Data
Bridge height and weight app

http://whitehtj.justfree.com/maps/bridges.php


Overview
This web based application uses the Warwickshire bridge height
restrictions data and the Warwickshire bridge weight restriction which
is displayed via Google maps.

The Application

Both of the restriction dataset were imported into MySQL database.
A single dynamic web page extracts the data from the database and
instantiates some JavaScript objects in order to manage the bridge
data.

Bridges are displayed on the map depending on what is selected on the
dropdown menu. Selecting a bridge on the map will give details of the
bridge. Selecting the bridge in the menu box will not only display the
detailed bridge information but also zoom in on the bridge location.
There is also a feature to enter the height and weight of a vehicle
via the ‘Filter’ button which results in only the bridges been
displayed that are unsuitable for the vehicle to pass over or pass
under.

This application took around three days to create, the code behind it
does have room for improvement and I do apologise for the poor layout
and the use of HTML tables!


Issues
Firstly I have found some possible errors with the height restriction
dataset, these are currently under investigation. The errors concern
the following bridges :-

Birmingham Rd Canal (A425/01) Easting 427087 Northing 265615
Bishoption Park and Ride (C93/15) Easting 418682 Northing 256834
Crackley Wood ( D5069/02 ) Easting 428831 Northing 274339

There is some room for improvement in these datasets. Both datasets
would benefit from having longitude and latitude coordinates
documented. These can be derived as in this application but it would
be an improvement to have these coordinates added at source in order
to reduce the risk of errors in translation.
The ‘Signed Headroom’ column does not state the units, they are
assumed to be in metres. Ideally the ‘Weight Limit’ column should
consist as two separate columns one for ‘PWL in tons’ and the other
‘Axel Limit in tons’, this would alleviate the need to parse text to
find the limit.

For the future
I haven’t really looked but I would like to think that there was some
sort of UK standard for this type of information. If not I would have
thought it worth while to have a set of standardised datasets for the
whole of the UK.

Finally
Can you find the bridge with a limit of zero tons?

Terry

James

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May 13, 2010, 5:52:16 PM5/13/10
to Warwickshire Open Data
Dicks Lane Canal Bridge

James

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May 13, 2010, 3:16:42 PM5/13/10
to Warwickshire Open Data
Dicks Lane Canal Bridge
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