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9.7.1 Monitoring Process for Lancashires AQMAs
In addition to LTP8, each Lancashire AQMA will be monitored individually and the results, combined with outcomes, will be included in Annual Progress Reports. This reporting will use traffic data with a base year of 2004/5 and a target year of 2010/11.Diffusion tubes are the preferred method of obtaining accurate air quality data. A comparison of observed and modelled results shows that diffusion tubes provide a consistent approach for all Lancashire’s AQMAs, whilst calculated results do not provide a true representation of air quality. Local influences were deemed the source of the differences in concentration levels. Modelling, however, is required to determine the impact of measures from the ‘do nothing’ scenario.
Air quality is modelled using the DMRB Screening Method 1.02 and the results are used to determine the net differences between a ‘do nothing’ and a ‘do something’ scenario. The ‘do something’ includes the effects on air quality from identified packages of work which will form part of the Action Plan of an AQMA. This procedure has been undertaken for Lancaster. As other Action Plan measures are finalised and agreed through consultation, their impacts will be calculated and used to update Lancaster's mandatory indicator and trajectory. This process will be replicated for all AQMAs and included in Annual Progress Reports.
9.7.2 Observed Air Quality Data NOx
Air quality is continuously monitored using diffusion tubes and the results are published by Local Authorities. Diffusion tube locations are carefully chosen to represent an AQMA. Tubes are located either mid link or near the critical junction, dependent on the AQMA. They are generally attached to lampposts or buildings at a height of 2 metres. However, in isolated locations concentrations may be higher or lower than those observed. To take account of over and under-read diffusion tubes, all results are bias corrected to establish their annual mean.The current trajectory is based on 2 years continuous monitored data. When the results for 2005 (bias corrected) are available, they will be used to update the ‘do nothing’ trajectory.
9.7.3 Traffic Flow
Traffic flow into each AQMA will be monitored between 07:00 and 10:00, as for indicator LTP6. The Average Annual Daily Flow on AQMA links will also be monitored .Where an AQMA includes highway links that are monitored for indicator LTP6, or are a continuation of those links, it is expected that the LTP6 target will be exceeded. On these links the Council will aim to have no increase in traffic flows during the peak period with a slight reduction during the peak hour. On other links that form AQMAs it is expected that the LTP6 target will be achieved.
9.7.4 Air Quality and Traffic Flows in Lancashire
The following table is the summary of the air quality and traffic data within AQMAs. Where available, individual trajectories are shown. To indicate the overall level of success in improving air quality within Lancashire, combined air quality within Lancashire's AQMAs has been calculated, giving a Lancashire trajectory. A graphical representation of the Lancashire average exposure per resident to oxides of nitrogen is included in the AQMA section in the District chapters.
Table 9.7.4
Air Quality and Traffic Flows on Primary Links within AQMAs
Location and
Population
within AQMA
Traffic Flow and
Air Quality
2003/4 Observed
2004/5
Base year
Trajectory
2005/6
2006/7
2007/8
2008/9
2009/10
2010/11
Lancaster (Action Planning not complete)
City Centre Gyratory
Population 455
NOx mg/m 3
43
41
41
40.8
40.6
40.4
40.2
40.1
AADF
NB
SB
20200
16190
20200
16110
20031
15941
19862
15772
19693
15603
19524
15434
18024
16934
7-10am
3620
3560
3445
3330
3215
3100
3427
Preston (Action Planning in early stages)
Ringway
Church Street
Junction
a=North of Junction
b=South of Junction
Population 105
NOx mg/m 3
41
41
AADF
a
b
37180
26130
7-10am
a
b
3250
2230
3250
2230
3250
2230
3250
2230
3250
2230
3250
2230
3250
2230
Blackpool Road
Plungington Road
a=South of Junction
b=East of Junction
c=West of Junction
Population 38
NOx mg/m 3
36
43
AADF
a
b
c
8510
13970
11980
7-10am
a
b
c
980
1550
1650
990
1565
1666
1000
1581
1683
1010
1597
1700
1020
1613
1717
1030
1629
1734
1040
1645
1751
A59 Liverpool Road
Priory Lane
Cop Lane
(2)
a=West of Junction
b=North of Junction
c=South of Junction
Population 155
NOx mg/m 3
25 (3)
26
AADF
a
b
c
28430
2430
8240
7-10am
a
b
c
4460
180
1010
4505
182
1020
4550
184
1030
4595
185
1041
4651
187
1051
4687
189
1061
4734
191
1072
London Road
Victoria Road
Population 134
NOx mg/m 3
50 (3)
53
AADF
37950
37580
7-10am
6270
6260
6260
6260
6260
6260
6260
Leyland Road
Brownedge Road
a=North of Junction
b=South of Junction
Population 229
NOx mg/m 3
36 (3)
38
AADF
a
b
12800
8720
7-10am
a
b
1680
790
1697
798
1714
806
1731
814
1748
822
1766
830
1783
838
Station Road
(2)
Population 425
NOx mg/m 3
32 (3)
33
AADF
17100
7-10am
1579
1595
1611
1627
1643
1659
Average Exposure per Resident (4)
NOx m g/m 3
DO
42
42
44
46
47
49
51
53
RR
45
45
43
41
40
Notes
AADF=Annual Average Daily Flow 2 way, except Lancaster which operates as a gyratory
7-10am=Inbound flow only
DO=Do nothing (applies the Lancashire average current rate of air quality change)
RR=Required reduction to satisfy National Air Quality Strategy objectives
(1)
Measures include only those indicated in the Lancaster chapter. Further measures that will be included in the developed Action
Plan.
(2)
AQMAs excluded from average exposure calculation as they would artificially reduce overall values.
(3)
Values estimated.
(4)
Average Exposure per AQMA resident uses the following equation and is applied to each assessed year.
where n=number of AQMA
and Pop=population of each AQMA.
9.7.5 LTP8: Lancaster Mean Resident Exposure Reduction within AQMA
The following table indicates the calculated air quality impacts from packages of work on the City Centre AQMA. The impact of other schemes will be included when the Action Plan is accepted. A number of the identified schemes in the District Chapters have secondary benefits to air quality. In Lancaster, the Heysham M6 link benefits particular corridors including both river crossings but has only a slight impact on town centre movements and air quality.
Table 9.7.5a
Lancaster: Annual Mean Resident Exposure Reduction within AQMA
Package/Scheme
Reduction NOx m g/m 3
Heysham M6 Link
0.1
Lancaster City Centre Air Quality Zone
To be determined
Cycling Demonstration Project
0.1
Personalised Travel Planning
0.3
Morecambe West End Neighbourhood Scheme
Not Applicable
Park and Ride
0.4
ITS
Not Applicable
Total
0.9
The above impacts have been included in the ‘do-something’ trajectory which assumes that traffic growth is restrained and that the measures implemented reduce the AADF. The ‘do-nothing’ trajectory assumes the AADF growth will occur at the same rate as per the previous 5 years. Currently this is 0.2% increase per year.
Improvements to vehicle and fuel technology should make an important contribution to the improvement of air quality within AQMAs. However, their contribution is not being relied upon and their benefits are not included. If the technology benefits were taken into account, they would have sufficient impact to meet air quality objectives in a number of Lancashire’s AQMAs.
The following summary table contains Lancaster's observed annual mean exposure concentration and trajectories for both 'do nothing' and 'do something' situations. The 'do nothing' includes a factored Lancashire trajectory as a comparison. The table also includes the percentage change from base year. The year on year changes will be included in the Annual Progress Reports to showing the level of success in achieving the required change that satisfies the air quality objectives.
Table 9.7.5b
LTP8 Air Quality in Lancaster
Annual Mean Resident Exposure Reduction within AQMA m g/m 3
2003/4
Observed
2004/5
Base year
Trajectory
Notes
2005/6
2006/7
2007/8
2008/9
2009/10
2010/11
Lancaster
observed
43
41
N/A
Observed data 2005 not yet available
Lancaster
do nothing
41
41.0
41.1
41.1
41.1
41.2
41.2
Observed base value with calculated year on year traffic growth using DMRB
Lancashire
do nothing
41
43
44
46
48
50
52
Lancashire average trend factored to Lancaster’s base year
Lancaster
do something
41
41
40.8
40.6
40.4
40.2
40.1
Includes the impacts of the identified Lancaster District packages/schemes. Assumes uniform reduction over time.
Changes in Annual Mean Resident Exposure within AQMA % change from base year
2004/5
2005/6
Trajectory
% Increase per year
2006/7
2007/8
2008/9
2009/10
2010/11
Min
Max
Ave
Lancashire
do nothing
0
3.7
7.3
12.2
17.1
22
26.8
3.6
4.8
4.5
Lancaster
do nothing
0
0
0.2
0.2
0.2
0.5
0.5
0.0
0.3
0.1
Lancaster
do something
0
0
-0.5
-1.0
-1.5
-2.0
-2.4
-0.4
-0.5
-0.4
9.7.6 Risk Management of Air Quality Projects
Our Risk Management Strategy is described in detail in section 6.2. This overriding strategy will ensure that we deliver our air quality and other targets. Printer Friendly Version | About our website | Top of page | Environment Directorate Copyright © 2009, Lancashire County Council | Site Terms What's New | Site Map | (External) Tell us what you think about our site...