WSP
Transport Planning Project
The Project
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Introduce you to elements of the transport planning process
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A typical project or responsibility for WSP
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When a developer wants to build a new housing development they need to provide: information on
what impact the new houses and new residents will have on the local roads.
For example: Do the additional cars added to the local roads once the houses are built, cause
queuing at local junctions.
WSP provide written assessments and use computer programs to analyse whether the new
development will have a negative impact on the local roads and (if necessary) to what extent this
impact can be avoided or mitigated by paying for improvements to junctions or other transport
facilities.
This project introduces factors that need to be taken into account when considering the
traffic and transport impact that a new development will have.
Any new development will generate person trips, which represent people travelling to and
from the development for any purpose, be that work, school, shopping etc.
The Project Brief
• Consider the transport impact of a new residential
development of 500 houses (Units)
• Evaluate how the impact varies as you assign different
proportions of all the trips generated by the development to
different modes of transport (Car, Bus, Train, etc)
Project Information
• View the Network Diagram which shows the location of the new
development (the triangle with DEV inside).
• Other information shown on the diagram:
• ROADS which link to the new development (shown by straight black
lines)
• LOCAL JUNCTIONS (shown by circles - J1, J2, J3)
• BUS ROUTES along the roads (red dotted lines)
• BUS STOPS(red dots)
• Potential CYCLE LANE locations (green dashed lines).
• RAILWAY LINE with two stations
• BOAT/FERRY with two terminals
• 4 EMPLOYMENT AREAS (A, B, C & D), which can be reached using the
different modes of transport.
Decision Making
• To make decisions about how to distribute the trips go to:
– “Inputs” Worksheet of the Excel File “WSP Travel & Transport Project”
• The different transport modes shown on the diagram are:
– Train , bus, boat, car driver, car passenger, cycling and walking
• Different mode share distributions will have different impacts on the road
network and consequently will incur different financial costs.
Results
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The “NETWORK OVERVIEW” tab shows the following results of the Inputs:
– Number of cars at each of the junctions (shown by arrows),
– Remaining capacity at the junctions,
– Total number of trips to each employment zone by each transport mode.
Improvement Costs
• The “Reports” Tab, shows the following improvements that have been
triggered for each mode and their costs
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Junction Improvements
Bus Improvements
Car Park Improvements
Cycle Lane Improvements
• There is no 100% correct solution
• Correct solution will usually be dictated by the demands of clients or the
Local Highway Authority (e.g. Hampshire County Council)
• The solution which involves the lowest cost is likely to be most favoured by
the client, but may not be most favoured by the Local Authority.
Decision Choices
• Aim to arrive at a combination of mode shares which results
in the lowest overall costs incurred
• Aim to keep the mode shares to realistic levels
– example saying that very large proportions of people will get the bus
and not many people will drive is unrealistic.
• Assigning a mode share of less than 40% to car driver to any
of the zones is probably unlikely in the current climate, with
the possible exception of trips to employment A, which is
located closest to the new development.
INSTRUCTIONS
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Familiarised yourself with the 'Network Overview' and ‘Trip Gen’ tabs as detailed in the
introduction.
Section 1. Calculates the total number of trips that will be generated by the 500 houses.
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To work out the total number of trips you first need a trip rate, which in this case has already been
worked out and is 0.900.
In the peak hour (08:00 - 09:00) on average across the whole site there will be 0.9 trips per house. it is an
average across the whole site, there are some houses which will not make any trips in the peak hour, e.g.
elderly, unemployed or people who start work later.
Instructions (Continued).
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To obtain the total number of trips generated by the 500 homes the trip rate is
multiplied 500, to give a total of 450 trips.
These trips are then split down into the different transport modes, which here is
based on average national percentage splits for all trips.
For this project we are assuming that all peak hour trips are people travelling to
work, we are ignoring trips to school, so we now need to assign trips to the
different modes for each employment zone (A, B, C, & D). This is done under Point
2 on the 'Trip Gen' tab. To input changes to modes within A, B, C & D go to the
“INPUTS” Worksheet
Instructions (Continued).
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Once you have access the INPUTS WORKSHEET press Ctrl SHIFT M
This will take you to the Management Screen
Instructions (Continued).
• By changing the mode shares in the boxes, you can adjust the amount of
trips that are assigned to each mode for each of the four employment
zones in turn
• Each employment zone has already been given a percentage share of the
total number of trips (i.e. 10%, 20% or 50%), based on the number of jobs
available in that zone
• You will need to go through each of the employment zones in turn and
adjust the mode shares in order to redistribute the trips from the
development onto the different transport modes
• NOTE: Depending on the employment zone, only certain methods of
transport will be available to get to that zone.
• By changing the mode shares in certain ways you will incur costs
Instructions (Continued)
• The costs you will incur are summarised as follows:
• BUS: If the total number of trips going by bus from the development is
more than 70, you will trigger a cost for bus improvements. This
represents the cost of putting an extra bus onto the route to
accommodate the new trips
• Further bus improvements will be triggered if more than 120 trips are
assigned to bus
• NOTE: The number 70 represents the threshold for a significant modal
shift to bus, which is only likely to be achieved in reality if the bus service
frequency is increased.
Instructions (Continued).
• CAR: Junction improvements will be triggered if more than 50 car trips are
routed through junction 1, 100 car trips through junction 2, or 150 car
trips through junction 3.
• CYCLE: Cycle lane improvements will be triggered in order to make any
increases to the mode share assigned to cycling.
• CAR PARKING: Car parking improvements at the rail station and boat
terminal will be required and triggered in order to assign trips to this
mode of getting to the station/boat terminal.
Instructions (Continued).
• A summary of the costs that you will incur and the maximum number of
trips that can be accommodated by each of the improvements is provided
in Point 3. on the 'Trip Gen' tab
• Care should be taken that the number of trips made possible by each
intervention is not exceeded, i.e. no more than 50 cars can be
accommodated by each car park improvement and no more than 100
extra vehicles can be accommodated by the junction 1 improvements.
• As you make your mode share choices to each of the four employment
zones you can see (under Point 4.) how they impact upon the average trip
time per person (in minutes) to each zone. You can also see the average
cost to each person of their trip to work. These two factors should be
borne in mind when adjusting the mode shares to each zone.
Results
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Go to the ‘RESULTS' tab to see how your mode share decisions have affected the total costs
incurred and which specific improvements you have triggered
You can also see the remaining capacity of the junctions, together with a summary of the
number of trips by each mode to each zone.
The red and grey tabs are for information only and should not be edited. Editing should only
occur in the yellow tab.
MODE SPLIT
Overall Mode Across 4 Employment Zones
Total Mode Split
Train
124 27.23%
Bus
63 13.86%
Car Driver
149 32.67%
Car Pasr
43
9.41%
Cycle
14
2.97%
Walk
7
1.49%
Boat
56 12.38%
455
100.00%
RESULTS - IMPROVEMENTS
Junction Improvements:
J1
J2
J3
Yes
No
No
Bus Improvements:
-1 Bus
Yes
-2 Buses
Yes
Car Park Improvements:
At Rail Station
Yes
At Boat Terminal
Yes
Cycle Lane Improvements:
Required?
Yes
RESULTS - COSTS
Costs Incurred
Junction Improvements
Bus Service Improvements
Car Parking Improvements
Cycle Lane Improvements
Total Improvements Cost
£350,000
£240,000
£500,000
£75,000
£1,165,000
OVERALL COST of CURRENT MODEL
Overall Costs of Current Model
Average per Person Trip
Employment A
Employment B
Employment C
Employment D
Time (Hrs)
Cost (£)
13.20
18.80
18.85
33.40
£1.00
£2.90
£4.23
£10.30