HighwayTraffic Engineering Coursework 1

							Highway/Traffic Engineering Coursework 1
        Coursework for Dr. Underwood




             Ivan Thomson
                 BN0903A
               Dr. Underwood
                26MAR2005
                                         Table of Contents



Introduction                                                 iii

Question 1 – Traffic Management                              1

Question 2 – Channel Gullies and Safety Barriers             2

        Part A – Channel Gullies                             2

        Part B – Safety Barriers                             3

Bibliography                                                 4
                                          Introduction



This coursework is the result of the BN0903A coursework requirements for Dr. John Underwood. This
coursework attempts to satisfy all the requirements asked for.
                                      Question 1
                                   Traffic Management

The following maps show a town centre road network with three junctions marked (A, b
and C). There are sever congestion problems at junctions A and B due to vehicles
traveling from the north and turning right to gain access to the A77. Additionally, at
junction C there is a bad accident record involving traffic entering and exiting to and
from the minor access road.

Propose three different traffic management scheme/solutions to these problems:




                            1


                                      2
                                                             7
                                      3


                                      4
                     8
                                          5




                                                                        6
Discussion of Problem:

There are many ways you can approach this problem from reducing speeds, to posting signs, to the
introduction of mini-roundabouts through to synchronized traffic lights and blocking off roads.
Additionally, you could do something even more radical and introduce alternative routes outside the
immediate area in an attempt to encourage traffic not to go through the immediate area. But regardless of
what solutions are implemented it should be made clear that the solution only really solves the problem in
the immediate area and will most likely lead to transferring the problem elsewhere.

Three possible solutions to the problem(s) are listed below and following these solutions are additional
recommendations that should be considered:


Proposed Solution 1: - No right turns allowed

The inexpensive and quick solution:

By placing ‘No Right Turn’ signs at Junctions A & B for the south bound traffic you can eliminate all the
traffic turning right without performing any expensive alterations to the road layout. You will occasionally
get the impatient driver who will violate the restrictions, however, a majority of the traffic will obey the
signs and thus your problem of congestions due to right turning traffic will be eliminated at these junctions.
However, it should be noted that the problem will simply transplant itself at junctions along this route.

The problem at junction C can also be solved using signs and marking. By placing signs and marking that
prevent minor road traffic from turning left onto the major road and signs and marking that prevent west
bound major road traffic from turning right onto the minor road you can prevent the major road and minor
road traffic from crossing over each other and thus significantly reduce the number of accidents (of this
type) at this junction.


Proposed Solution 2: - Blocked road and no right turns allowed

The moderately priced solution:

At the location marked on the map with a red circle numbered ‘1’ (next to junction A) the road could be
blocked off creating a dead end in the residential area with points of entry and exit at the south side of the
area. A mini cul-de-sac would be created for the businesses at Junction A. The solution absolutely
prevents any traffic from turning right at junction A as there would no longer be a road there. However,
this action would transfer all traffic that would normally turn right at Junction A to Junction B and would
significantly increase the right-turning traffic at Junction B. To offset this right turns can be prohibited by
the use of signs and street marking at Junction B (as proposed in solution 1,).

The problem of accidents at Junction C can be solved by using the same method as mentioned in solution 1.

Proposed Solution 3: - mini-roundabouts

The more expensive solution:

The road located at the red circle marked ‘1’ should be closed and blocked off to create a dead in (as
mentioned in solution 2). The installation of a mini-roundabout at Junction B would give greater capacity
to the A78 since right turning cars would have much more opportunity to pass through because they would
have the right of way to complete their maneuver.

Junction C could be solved as well using a mini-roundabout. This would force cars to slow down and give
way thus significantly reducing accidents.
Additional Solutions & Discussion:

All numbered red circles on the map mark points of possible road closure or modification:

1 - This road should be closed as it would prevent any through traffic in the residential area and the
residents of the area would probably not object to this as it would significantly quiet the neighborhood and
increase the safety within the residential area.

2 & 3 – These roads should be blocked off to lower the points of access to the major road and to enhance
the neighborhoods. With less points of access to the major road the less obstructions to traffic.

4 – Entry and exit should be restricted to only south bound traffic. This would require modification of the
junction to prevent cars from crossing the major road while leaving this minor road and to prevent north
bound traffic on the major road from entering into this minor road. This would prevent any traffic at this
junction from crossing the major road, thus removing yet another obstacle to the major road traffic.

5 & 6 – both of this points should be narrowed and speed humps along the road should be introduced to
slow traffic along the road and to discourage drivers from using this minor road as a shortcut. This would
have the effect of reducing the number of cars crossing the major road at these two junctions and would
increase the safety for the pedestrians who access the park.

7 – Closure of the road at this point is considered if preventing any traffic from using the minor
neighborhood roads as shortcuts is desired. Additionally, cutting off the residential traffic from the
industrial traffic would have many benefits to the residents in the area.

8 – Closure of this road at this point would prevent access traffic so close to Junction B.

Speed Humps:

Speed humps could be introduced into the north-west residential area as a means of discouraging through
traffic access if road closure at point 1 was not desired or feasible.

Signs, Cameras and Markings:

Warning signs, speed limit signs, cameras and road marking could be placed along the major road near
Junction C to slow down the traffic to a more reasonable speed and to reduce accidents.

Pedestrianization of city centre:

Some pedestrianization measures of the city centre could be implemented to slow down the traffic through
this area and possibly discourage drivers from using this route altogether. Road narrowing, zebra crossing
and other pedestrian friendly measures may discourage many driver who’s destination is not the city centre
from entering this area altogether. They would then be force to find an alternative route elsewhere outside
the area. The problem then could be transferred to a more appropriate part of the city and be solved there.

Ring Road/Bypass:

A ring road or bypass road may be a solution if the traffic volume justifies the expense and if the
surrounding area allows for the construction of such a road. This solution would greatly reduce the amount
of traffic in the area. However, the impact to local business may not be acceptable or desirable.

Traffic Lights:

Traffic lights could be installed at Junctions B & C to control the flow and movement of the vehicles and to
help reduce accidents.
Rezoning:

Long term planning by the city council could incorporate a city plan whereby the industrial estate in the
immediate area could be phased out and slowly rezoned as a residential area. This would eliminate the
industrial traffic if that proves to be a key part of the congestion problem.

Roundabouts and mini-roundabouts:

Junctions B and C would greatly benefit from being turned into roundabouts or mini-roundabouts. This
would give vehicles crossing the roads greater and safer opportunities to do so, thus increasing capacity and
safety.

Approaches on major roads:

The approach on the A77 could include reduction in speed limit and warning signs early enough to prevent
vehicle queues from building up at Junction B.


Comment:

A traffic survey is needed to gather data in or do a proper analysis and to ensure the correct design
solutions are made. This also would be helpful in determining which design solutions will also be effective
in the long term as the traffic conditions change with time (either growing, stabilizing or decreasing).

A study of the surrounding area would be very helpful as well. This would give the traffic/road
engineering a much better understanding of the problem and this study may bring to light solutions not
apparent on the micro-level. One such example may be a solution 5 or 10 miles up the road that would
have a direct impact on the through traffic in this area.
                                     Question 2
                           Channel Gullies and Safety Barriers




Part A – Channel Gullies




Part B – Safety Barriers
                              Bibliography




Cover Picture: Unknown. J0400467.jpg. Available from: World Wide Web:
http://office.microsoft.com/clipart/results.aspx?lc=en-
us&Scope=MC%2CMM%2CMP%2CMS&Query=j0400467 [Accessed on 28 March
2003] [Royalty free clip art photo from Microsoft web site]