UWE Bristol Engineering showcase 2015

William Parry
Mechanical Engineering MEng
Project Supervisor
Dr Aruna Palipana
Environmental Impact of City Traffic Problems and Low Cost Solutions to
Such Problems
Introduction
There are many problems with the UK road network causing reduced traffic flow, congestion and higher emissions, with government and councils proposing
solutions which could cost the tax payer money and take finances away from other important parts of UK public services. This project propose low cost
solutions to such problems and also the environmental benefit of these solutions.
Project summary
Finding methods of improving current traffic
systems
Station road left turn to Filton Avenue, Filton
This left turn was analysed and it was found that there was a high demand
for the left turning however, there was a unnecessary stationary traffic that
could compromise air quality and reduce traffic flow. A left filter was
proposed as it would be possible to allow this traffic to flow for a majority of
the traffic light sequence. An increase in length for the designated left lane
and the relocation of a bus stop were also suggested to improve traffic flow.
Cyclists impact on traffic flow
To show the effect cyclist have on
traffic flow an experiment was
planned to find the average speed
of vehicles with and without
bicycles in front of the vehicles. A
50m length of road was used and
timings were taken to find the
speeds. The average delay caused
by the cyclists was found to be
3.350 seconds.
1
2
Using the average speeds for both
with and without bicycles it was
possible to find the corresponding
emissions at these speeds in grams
per kilometers (this was for a
specified light duty vehicle). This
was divided by the length used in
the experiment and the extra mass
of CO2, produced by the vehicle,
caused by the cyclist was found.
Addition of filter
light
Relocation of bus
stop
Increase
lane
length
It was found that on average, over
the 50m, that 2 grams of extra CO2
were produced when following a
cyclist. This is a relatively low value
however with Bristol having a large
number of cyclists it is important to
look at this on a larger scale. This
experiment showed the importance
of cycle lanes being used correctly.
Project Objectives
Evaluating problem traffic locations and
aiming to improve traffic flow and air quality
Project Conclusion
Over the course of the project, many problem
locations around north Bristol were looked
into. This meant that in the entirety of Brisotl
the number of problem locations would
surely increase. The cost of changing all these
areas may come to a large amount. Maybe
changes to the entire road network and driver
behavior (like the speed limit reduction) could
provide more large scale cost effective
benefits.
Reduced speed limits effect on traffic flow
Over the past year many areas of roads in Bristol
have lowered there speed limits 20 mph. This
scheme aims to encourage transport via walking
cycling and public transport. There is also evidence
to support the theory that city traffic travels more
efficiently when travelling at 20mph.
Approximate date that large 20 mph
sign were painted on the road surface
If traffic is theoretically flowing better then there
should be a decrease in NO2. Data for NO2 levels
over the past three years was studied and it was
noted that after the introduction of road signs
there was lower than average levels of NO2. This
provides evidence that this change may increase
traffic flow. However, this decrease in NO2 was
seen recently and more research is needed.