Traffic Analysis of Celia Crescent– February 2017 Martin Shortland shashf / 170102 1 1.0 Introduction 1.1 Motion has been instructed by Martin Shortland to provide an appraisal in relation to the existing traffic situation on Celia Crescent and the surrounding roads located within Ashford. Celia Crescent falls within the administrative boundaries of Spelthorne Borough Council (SBC) and Surrey County Council (SCC). Background 1.2 Celia Crescent comprises a set of streets with a primary function of providing access to a number of residential properties and is therefore only intended to provide access for local traffic. The narrow carriageway and pavement widths and the residential nature of Celia Crescent make it unsuitable for carrying high levels of through traffic or large vehicles. 1.3 It is understood that the section of Celia Crescent that provides access to Kingston Road is being used as a rat running route for traffic seeking to avoid the signalised Woodthorpe Road / Kingston Road junction to the west. Rat running is the practice of drivers using secondary roads or residential side streets instead of the intended main roads in urban or suburban areas. The identified rat running route is shown in Figure 1.1 below. Figure 1.1: Identified Rat Running Route 1.4 Concerns relating to this matter have been raised by local residents in representations to SCC who have subsequently and informally consulted on 3 possible options to restrict the use of Celia Crescent as a through route. 1.5 Whilst a preferred option has been preliminarily identified by residents following consultation with SCC, it has been requested that the technical detail of each option is considered further to ensure that any option taken forward represents the most appropriate approach. 8 Duncannon Street London WC2N 4JF Tel: 020 7031 8141 www.motion-uk.co.uk Technical Note 1: Traffic Appraisal of Celia Crescent Project: Celia Crescent - Transport Consultancy Services Prepared by: James Werby Approved by: Damian Tungatt Date: 24/02/2017 Page 181
72
Embed
Meetings, agendas, and minutes...numbers 170102-TK02A and 170102-TK03A, attached within Appendix D. Drawing 170102-TK02A demonstrates the significant overrun of both an HGV and a car
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Traffic Analysis of Celia Crescent– February 2017
Martin Shortland
shashf / 170102 1
1.0 Introduction
1.1 Motion has been instructed by Martin Shortland to provide an appraisal in relation to the existing traffic
situation on Celia Crescent and the surrounding roads located within Ashford. Celia Crescent falls within the
administrative boundaries of Spelthorne Borough Council (SBC) and Surrey County Council (SCC).
Background
1.2 Celia Crescent comprises a set of streets with a primary function of providing access to a number of
residential properties and is therefore only intended to provide access for local traffic. The narrow
carriageway and pavement widths and the residential nature of Celia Crescent make it unsuitable for
carrying high levels of through traffic or large vehicles.
1.3 It is understood that the section of Celia Crescent that provides access to Kingston Road is being used as a
rat running route for traffic seeking to avoid the signalised Woodthorpe Road / Kingston Road junction to
the west. Rat running is the practice of drivers using secondary roads or residential side streets instead of
the intended main roads in urban or suburban areas. The identified rat running route is shown in Figure 1.1
below.
Figure 1.1: Identified Rat Running Route
1.4 Concerns relating to this matter have been raised by local residents in representations to SCC who have
subsequently and informally consulted on 3 possible options to restrict the use of Celia Crescent as a
through route.
1.5 Whilst a preferred option has been preliminarily identified by residents following consultation with SCC, it
has been requested that the technical detail of each option is considered further to ensure that any option
taken forward represents the most appropriate approach.
8 Duncannon Street
London
WC2N 4JF
Tel: 020 7031 8141 www.motion-uk.co.uk
Technical Note 1: Traffic Appraisal of Celia Crescent
Project: Celia Crescent - Transport Consultancy Services
Prepared by: James Werby
Approved by: Damian Tungatt
Date: 24/02/2017
Page 181
Traffic Analysis of Celia Crescent– February 2017
Martin Shortland
shashf / 170102 2
1.6 This Technical Note therefore builds on the initial work undertaken by SCC and gives further consideration
to the current traffic conditions. The potential options to prohibit the use Celia Crescent as a rat running
route are then considered to ensure that local amenity and highway safety would not be negatively
impacted.
2.0 Baseline Traffic Conditions
2.1 To ascertain existing traffic conditions, an independent traffic survey company was commissioned to install
an Automatic Traffic Counter (ATC) on Celia Crescent north of its junction with Kingston Road between
13/01/2017 and 19/01/2017. The location of the ATC and full outputs of the survey data are provided at
Appendix A, whilst a summary of the daily traffic flows recorded from 00:00 to 24:00 hours are provided
in Table 2.1 below.
Fri Sat Sun Mon Tues Wed Thurs Average traffic
for 7 days
Northbound 340 179 128 239 217 216 214 219
Southbound 505 446 307 551 529 559 571 495
Total 845 625 435 790 746 775 785 714
Table 2.1: Surveyed Traffic Flows from 00:00 – 24:00 hours on Celia Crescent (all vehicles)
2.2 It is evident from the data in Table 2.1 that the (7 day) average two-way traffic flows between 00:00 and
24:00 hours on Celia Crescent totals 714 vehicles, with Friday having the highest two-way flows of 845
vehicles. The 7 day two-way traffic throughout the week between 00:00 and 24:00 hours on Celia Crescent
totals over 5,000 vehicles. These results highlight that the section of Celia Crescent near its junction with
Kingston Road is heavily trafficked throughout the week and carries significantly more traffic than expected
for a residential street.
2.3 Of the total 5,001 recorded 7 day two-way movements, 22 vehicles were recorded as being Heavy Good
Vehicles (HGVs) and 377 vehicles were recorded as light goods vehicles (LGVs).
2.4 As demonstrated above, there are a large number of vehicles using Celia Crescent, particularly on
weekdays, with 3,941 out of the 5,001 (79%) vehicle movements being attributed to weekday traffic. Table
2.2 summarises the traffic flows associated with the weekday AM peak hour period.
Fri Mon Tues Wed Thurs Average traffic for
5 days
Southbound - AM Peak
(08:00 – 09:00 hours) 83 96 82 92 86 88
Table 2.2: Surveyed Southbound Traffic Flows from 08:00 – 09:00 hours on Celia Crescent (all vehicles)
2.5 Based upon the information presented in Table 2.2 it is evident that the (5 day) average southbound traffic
movements in the morning peak hour period between 08:00 and 09:00 hours on Celia Crescent totals 88
vehicles, with Monday having the highest southbound traffic flow of 96 vehicles. The morning peak hour
traffic flows represent between 12-17% of the total weekday daily (00:00 to 24:00 hours) southbound
traffic.
2.6 In addition to the above, an ATC was also installed by SCC along the straight east-west section Celia
Crescent between 07/09/2016 and 14/09/2016. The results of this ATC are attached at Appendix B. The
total 7 day two-way vehicle flows recorded in this location between 00:00 to 24:00 hours total 6,494
vehicles. The difference of approximately 1,500 movements throughout the week between the ATC
commissioned by Motion and the ATC commissioned by SCC could be attributed to traffic exiting (and
entering, even though prohibited) Fordbridge Park to the east of Celia Crescent generating a significant
number of additional movements.
Page 182
Traffic Analysis of Celia Crescent– February 2017
Martin Shortland
shashf / 170102 3
3.0 Estimated Trip Generations
3.1 The level of traffic that would reasonably be expected to use Celia Crescent can be estimated by giving
consideration to the TRICS database. TRICs contains survey data for different land uses broken down by
vehicle type and time period. By interrogating the TRICS database it is possible to generate an estimated
trip rate per household for an area similar in location and nature to Celia Crescent.
3.2 Similarly, data has been obtained from the Post Office postcode information website to establish the
number of dwellings in the locality that would reasonably be expected to use Celia Crescent to gain access
to their property. In some instances a reasonable estimate has been made in respect of route.
3.3 The Post Office records highlight that Celia Crescent is made up of approximately 60 properties, however in
this assessment it is not assumed that all residents would route south towards Kingston Road to leave the
Crescent, with some being assumed to route north via Woodthorpe Road. Therefore, for a robust analysis it
has been estimated that trips associated with 40 properties would likely route through Celia Crescent as
part of a normal journey. The estimated trip rate and the number of movements that these properties
would be expected to generate during the morning and evening peak hour periods and throughout the
course of the day is summarised in Table 3.1 below, with the full TRICS output report within Appendix C.
Time Period Arrivals Departures Two-Way
Trip Rate Vehicle Trips
Trip Rate Vehicle Trips
Trip Rate Vehicle Trips
Morning Peak Period (08:00 to 09:00 hours)
0.141 6 0.389 16 0.530 22
Evening Peak Period
(17:00 to 18:00 hours) 0.362 14 0.165 7 0.527 21
Daily
(07:00 to 19:00 hours) 2.305 92 2.354 94 4.659 186
Table 3.1 TRICS trip rates for Celia Crescent (based on 40 dwellings)
3.4 Applying trip rates established from an interrogation of the TRICS database indicates that circa 22 and 21
two-way vehicle movements in the weekday morning and evening peaks respectively are likely to be
generated by the existing dwellings on Celia Crescent, and circa 186 movements over the course of the
day.
3.5 For comparative purposes the average 5 day, daily (07:00 - 19:00 hours) vehicle movements recorded by
the ATC have been interrogated and compared against the data obtained from TRICS based on the
movements generated by 40 dwellings. The difference when comparing the two-way vehicle flows from
TRICS and the recorded survey data are summarised in Table 3.2 below.
Time Period Local Traffic Based on TRICS
Recorded Traffic by ATC
Difference in Traffic
Morning Peak Period (07:00 to 08:00 hours)
22 105 +83
Evening Peak Period
(17:00 to 18:00 hours) 21 55 +34
Daily
(07:00 to 19:00 hours) 186 679 +493
Table 3.2: Comparison of trip generation for Celia Crescent against the recorded survey data
3.6 It is evident that 83 and 34 movements in the AM and PM peak hour periods respectively and 493
movements throughout the day (07:00 to 19:00 hours) are estimated to be attributed to rat running
traffic. This demonstrates that Celia Crescent is subject to 365% increase in the traffic volume that would
typically be expected on a road of this nature.
Page 183
Traffic Analysis of Celia Crescent– February 2017
Martin Shortland
shashf / 170102 4
4.0 Highway Appraisal
4.1 Given that Celia Crescent provides access to a small number of dwellings, which would generate a relatively
low number of vehicle movements, it would normally be expected that the traffic on Celia Crescent would
comprise of mainly local / neighbourhood traffic only. Therefore, the high volume of vehicles recorded as
using Celia Crescent confirms that it is being used as a rat run to avoid the Woodthorpe Road / Kingston
Road signalised junction. It also provides the only point of exit from Fordbridge Park.
4.2 The number of HGVs and LGVs recorded travelling down Celia Crescent is also higher than expected as
these vehicle types would not normally have any regular business along Celia Crescent. However,
Woodthorpe Road and Kingston Road including the signalised Woodthorpe Road / Kingston Road junction
are designed to accommodate larger volumes of traffic including HGVs and LGVs and therefore should carry
the traffic that currently uses Celia Crescent.
4.3 The large vehicle flows that comprise a mix of HGVs, LGVs and cars could increase potential conflict
between vehicles as the section of Celia Crescent towards Kingston Road is a relatively narrow street. The
footways on either side of this section of Celia Crescent are also relatively narrow. Due to the narrowness
of the carriageway, the footways are often subject to vehicles overrunning them in order to avoid collisions
/ conflict with oncoming vehicles. This has resulted in many instances of local residents having to move out
of the way of oncoming vehicles mounting the pavement. These incidences have been reported by
residents through witness statements, ongoing correspondence with SCC and photographic evidence.
4.4 The tight turning radii when entering this section of Celia Crescent also contribute to problems and results
in vehicles (especially HGVs and LGVs) considerably overrunning the footway. The vehicle tracking
movement of 2 vehicles along Celia Crescent at an identified pinch point is demonstrated on drawing
numbers 170102-TK02A and 170102-TK03A, attached within Appendix D. Drawing 170102-TK02A
demonstrates the significant overrun of both an HGV and a car onto the footway at either end of Celia
Crescent in order to avoid a collision, whilst drawing 170102-TK03A demonstrates the same scenario but
with a LGV and car. Images attached within Appendix E illustrate vehicle tyre tracks on the footway and
further demonstrates such potentially dangerous overrunning occurs. It is also reported by residents that
vehicles regularly do not give way to allow other vehicles to pass meaning that overrunning onto the
footways a frequent occurrence.
4.5 It is evident that this practice poses potential safety concerns for pedestrians walking on either of the
footways on Celia Crescent and increases the risk of vehicle conflict. Previous incidents in this particular
location have included vehicles crossing the pavement and striking property boundary walls. Contributing
factors include, but are not limited to, the poor road surface (especially when wet) and vehicle positions on
the road as the narrow carriageway width.
4.6 In addition to the above, Celia Crescent experiences specific issues with drainage, which during wet periods
of the year regularly leads to significant flooding of the carriageway as evidenced in Figure 4.1. The rat
running exacerbates the drainage issue as vehicles continue to travel down Celia Crescent.
Page 184
Traffic Analysis of Celia Crescent– February 2017
Martin Shortland
shashf / 170102 5
Figure 4.1: Result of Drainage Issues on Celia Crescent
5.0 Potential Mitigation Measures
5.1 There are 3 potential options that have been considered in order to mitigate the impacts of rat running
through Celia Crescent onto Kingston Road. These options seek to improve the general amenity and safety
of residents. The options are as follows:
► Option 1 - considers blocking off access to Celia Crescent from Woodthorpe Road (at the Celia Crescent
/ Woodthorpe Road junction) by signage as illustrated in drawing 170102-02, attached within
Appendix F.
► Option 2 - considers blocking access to the Celia Crescent / Kingston Road junction via the potential
introduction of bollards on Celia Crescent in the location illustrated in drawing 170102-03, attached
within Appendix G.
► Option 3 - considers prohibiting all access to Kingston Road via Celia Crescent through the potential
introduction of a physical barrier such as a manual swing arm gate as illustrated in drawing 170102-
04A, attached within Appendix H.
Page 185
Traffic Analysis of Celia Crescent– February 2017
Martin Shortland
shashf / 170102 6
Assessment of Potential Options
Option 1
5.2 Option 1 would seek to restrict eastbound traffic at the Celia Crescent / Woodthorpe road junction to access
only through the use of signage. This option would restrict vehicles from cutting through Celia Crescent
onto Kingston Road. However this proposal is unlikely to deter all drivers from using the rat run and is
likely to be problematic to enforce. Vehicles coming from Fordbridge Park would not be stopped from using
the section of Celia Crescent leading to Kingston Road.
Option 2
5.3 Option 2 considers the potential introduction of bollards on the straight east-west section of Celia Crescent.
The bollards would be removable in case of access being required by emergency vehicles. However, it is
noted that Celia Crescent is a residential street and it is unlikely that this route would be regularly used by
emergency vehicles. However, if emergency access through Celia Crescent onto Kingston Road is required,
then the bollard would be removable via unlocking a padlock so that it can be taken out of its fixing.
Specifications of an example bollard that could be implemented are attached within Appendix I. It should
be noted that the proposed bollards would not prohibit cyclists or pedestrians from using the Crescent.
5.4 The introduction of these bollards would stop vehicular traffic from Woodthorpe Road accessing the section
of Celia Crescent that links onto Kingston Road and would therefore stop rat running from the west.
However, much like Option 1, potential vehicles coming from Fordbridge Park would not be stopped from
using the section of Celia Crescent leading to Kingston Road. Some residents within Celia Crescent would
also lose direct access onto Woodthorpe Road and free movement throughout the Crescent would be
restricted.
Option 3
5.5 Option 3 proposes to stop all access onto Kingston Road from Celia Crescent via a physical barrier, which is
illustrated as a manual swing arm gate that will span the width of the road. An example of the type of
specification of the manual swing arm gate is attached at Appendix J. Drawing 170102-04A (Appendix H)
illustrates where the swing arm gate would be positioned and also indicates that access will be for
emergency vehicles only. In general daily use it should be kept clear by all other vehicles. This option
would stop access from the west from Woodthorpe Road and the east from Fordbridge Park onto the
section of Celia Crescent to Kingston Road. However, this option also stops all residents, including those
living on this section of Celia Crescent from accessing Kingston Road. This would add to some residents’
journey time when leaving their place of residence as well as adding a small amount of traffic on other
junctions such as the Celia Crescent / Woodthorpe Road junction. However, by prohibiting access onto
Kingston Road, all residents would have the same access onto the surrounding road network, which will
reduce the possibility of disputes regarding access onto Kingston Road.
5.6 It is considered that Option 3 is the solution that addresses the majority of the issues raised by residents
within the local area. Whilst Options 1 and 2 contribute to stopping the majority of traffic from Woodthorpe
Road, they do not restrict vehicles travelling from Fordbridge Park using Celia Crescent to access Kingston
Road. It is noted that Fordbridge Park currently hosts large scale events, which bring high numbers of
visitors to the area and consequently vehicular traffic. It is understood that a new pavilion is currently
being constructed within the park. This has the opportunity to increase the likelihood of larger events
taking place more regularly.
5.7 Consequently, this will lead to more visitors and more traffic coming to the area, which will increase the
vehicular flows on Celia Crescent. If either Option 1 or 2 were implemented it is anticipated that these
vehicles would still have the potential to use the narrowest section of Celia Crescent leading to Kingston
Road when exiting the park to join back onto the surrounding road network, whereas Option 3 would
prohibit this and ensure the vehicles leave by the wider, more appropriate route.
Page 186
Traffic Analysis of Celia Crescent– February 2017
Martin Shortland
shashf / 170102 7
5.8 It would therefore be preferable to direct vehicles to the Woodthorpe Road/Celia Crescent junction. Whilst
this would direct traffic onto the straight east-west section of Celia Crescent, where cars could potentially
travel in excess of the posted speed limit, it is noted that speeding is not a problem along any part of the
Crescent.
Summary
5.9 Option 3 is considered to be the most suitable in addressing most of the issues raised by residents and is
the option that is considered to bring with it the least number of negative issues. Vehicles from both the
east and west would no longer have access to Kingston Road via Celia Crescent. Although this also applies
to the existing residents on the southern section of Celia Crescent, the relatively small number of vehicle
flows generated by residents is considered likely to result in only a minimal impact on the immediate
surrounding highway network. Furthermore, Option 3 would still enable the free movement of traffic of
existing residents around the crescent.
6.0 Refuse Collection
6.1 It should be noted that by introducing Option 3, refuse vehicles would not have access from this section of
Celia Crescent onto Kingston Road. Therefore, it is proposed that refuse vehicles would reverse down Celia
Crescent to service the necessary dwellings and then exit in a forward direction before turning left onto
Celia Crescent and gaining access to Woodthorpe Road as illustrated in drawing 170102-TK01A, attached at
Appendix K. The size of the vehicle demonstrated in this drawing is based upon Spelthorne Borough
Council’s Guidance on the Storage and Collection of Household Waste (updated November 2012).
6.2 It is understood that this arrangement currently takes place throughout the crescent on the residential
roads opposite to where the mitigation measure would be implemented. It is noted that these roads
measure approximately 125 metres, while the section of Celia Crescent being blocked off measures only 80
metres. Therefore, this proposed arrangement should not cause any highway issues as it is already in
occurrence on longer roads in the surrounding area.
7.0 Summary and Conclusions
7.1 Motion has been engaged by Martin Shortland to provide a traffic appraisal in relation to the existing traffic
situation on Celia Crescent and its surrounding roads located within Ashford. Celia Crescent is a residential
road that provides access to a number of residential dwellings and should only be used for carrying local
neighbourhood traffic.
7.2 It has been demonstrated that Celia Crescent is subject to a high proportion of rat running traffic as
vehicles seek to bypass the Woodthorpe Road / Kingston Road signalised junction. The assessment in this
note has demonstrated that Celia Crescent is subject to 365% of the traffic volumes that would typically be
expected on a road of this nature. This is consequently having a negative impact on residential amenity of
residents at Celia Crescent and has the potential to cause accidents where vehicles overrun the footway.
7.3 To mitigate and address the amount of traffic using Celia Crescent, SCC informally consulted on 3 possible
options, which have been considered in more detail in this note. It is recommended all access to Kingston
Road from Celia Crescent is restricted by prohibiting this movement through a manual swing arm gate, as
outlined in Option 3.
7.4 As a result of blocking this through access, general traffic would be expected to utilise the main routes
more suitable for through traffic and therefore the negative impacts that are currently associated with rat
running traffic such as reduced residential amenity and decreased highway safety would be significantly