The presentation discusses key aspects of road networks including: 1. A brief history of early road transport methods and the development of road networks in ancient empires and by the Romans. 2. The classification and hierarchy of road networks including motorways, trunk roads, and local roads. 3. Important considerations for road network design such as connectivity, capacity, and accessibility. 4. An overview of Nigeria's extensive network of federal, state, and local roads and some of the challenges faced.

1. PRESENTATION ON ROAD NETWORK
BY
LAWAL SANI
SPS/15/MCE/00028
DEPARTMENT OF CIVIL ENGINEERING
BAYERO UNIVERSITY KANO
COURSE: CIV 8330
COURSE LECTURER: DR H. M. ALHASSAN
SEPTEMBER, 2016

2. ● The first methods of road transport were horses, oxen or even humans carrying goods over
dirt tracks and the Persians later built a network of Royal Roads across their empire.
● Romans built great roads with crushed stone for armies to be able to travel quickly.
● A road is a thoroughfare, route, or way on land between two places that has been paved or
otherwise improved to allow travel by foot or some form of conveyance, including a motor
vehicle, car, bicycle, or horse.
●This provide accessibility for potential of opportunities for interaction (Hansen 1959 and
Martellato et all, 1998).

3. ● As states developed and became richer, especially with the
Renaissance, new roads and bridges began to be built.
● The major road network is defined by the Department for Transport
England as “the network of motorways, trunk roads and principal roads
that serve the country’s strategic transport needs.

4.  Road construction improved slowly, initially through
the efforts of individual surveyors such as John Met
calf in Yorkshire in the 1760s(a b Webb. English Local
Government. pp. 157-159).
 India has an extensive road network of 4.24million
km– the second largest in the world (MORTH, 2005).

5. ●Nigeria is a large country with the longest network of roads
morthan any country in Africa. Road statistics are not up to
date but there are 36,000 kilometers of federal roads linking
every part of the country. There are 30,000 kilometers of
states’ roads and 85,000 kilometers of local government
roads

6.  A roads – major roads intended to provide large-scale transport links
within or between areas.
 B roads – roads intended to connect different areas, and to feed traffic
between A roads and smaller roads on the network
 Classified unnumbered – smaller roads intended to connect together
unclassified roads with A and B roads, and often linking a housing estate or
a village to the rest of the network, known unofficially as C roads.
 Unclassified – local roads intended for local traffic. The vast majority
(60%) of roads in the UK fall within this category.

7.  Strategic Road Network System:
 Is the first system designed to cover national level
journeys, made of the nation's busiest and most
important inter-urban roads.
 Primary Route Network System:
 The primary route network (PRN) was introduced in
the 1960s. This designates routes between major
settlements and important destinations across the UK,
with the aim of providing clear ways to access most
places.

8.  •Transportation or mobility, communication and security.
 •Access to various activities.
 •water and energy supply.
 • Social and economical development
 Accessibility can thus be improved, among others, through the
following road interventions:
 1. Expansion of the road network, inclusion of new nodes.
 2. Reduction of the distance between the node and the nearest entry
of road network
 3. Increasing the amount of direct connections between a node and
the other nodes
 4. Increasing the number of links accessing the node
 5. Reduction of travel costs of road users, travel time, fares, toll
fees, vehicle operation costs, accidents, congestion (John, 2005).

9.  Designing successful transportation networks requires;
●The involvement of stakeholders.
●A step by step design process. Which include;
▪Structure – element.
▪High scale level – low scale level.
▪Collective – individual.
▪Ideal – existing.
▪Quality – capacity.
▪Access point – network.
▪Function - layout

10.  ● Transportation Network Design Problem (NDP), by
(Assoc. Prof. Dr. Huseyin Ceylan Pamukkale University) is concerns the
configuration of a network to achieve specified objectives.

11.  Network design problems.
 There are two forms of the problem
●The continuous network design problem; which takes
the network topology as given and is concerned with
the parameterization of the network. For example;
 The determination of road width (number of lanes);
 The calculation of traffic signal timings;
 The setting of user charges (public transport fares, road
tolls, etc).

12. ●The discrete network design problem. This is
concerned with the topology of the network. For
example:
 –A road closure scheme;
 –The provision of a new public transport service
(represented as a new set of links);
 –The construction of a new road rail link, perhaps a
bridge, a tunnel or a by-pass.

13.  Link connection and nodes.

14.  Lane addition.

15.  Building reversible lane.

16.  Congestion pricing.

17. Widening traffic lane.

18.  Road surfacing.

19.  Signal control intersection

20.  Intelligent transportation system.

21.  Traditional network design (Assoc. Prof. Dr. Huseyin
Ceylan Pamukkale University)
 Traditional network design has been concerned with the
minimization of system cost (equal to the sum of link flows
times the link costs).
 ci : the cost (travel time) on link i
 vi : the flow on link i (TRAFFIC ASSIGNMENT)
 si : the value of the design parameter for link i

22.  Traffic assignment.
 The major aims of traffic assignment procedures are:
 –To estimate the volume of traffic on the links of the network,
 –To obtain aggregate network measures, e.g. total vehicular flows, total
distance covered by the vehicle, total system travel time.
 –To estimate zone-to-zone travel costs(times) for a given level of demand.
 –To obtain reasonable link flows and to identify heavily congested links.
 –To estimate the routes used between each origin to destination(O-D) pair.
 –To obtain turning movements for the design of future junctions.

23.  The types of traffic assignment models:
 –All-or-Nothing assignment,
 –Incremental assignment,
 –User-Equilibrium (UE) assignment,
 –System Optimum (SO) assignment,
 –Stochastic User-Equilibrium (SUE) assignment,

24.  The trips from any origin zone to any destination zone
are loaded onto a single, minimum cost, path between
them.

25.  Wardrop’s Principles
 •John Glen Wardrop (1920 - 1989) was an English transport analyst who developed Wardrop's
first and second principles of equilibrium.
 The concepts are related to the idea of Nash equilibrium in game theory developed separately.

 Wardrop's first principle states: The journey times in all routes actually used are equal and less
than those which would be experienced by a single vehicle on any unused route.
 Each user non-cooperatively seeks to minimize his cost of transportation. The traffic flows that
satisfy this principle are usually referred to as "user equilibrium" (UE) flows, since each user
chooses the route that is the best. (Assoc. Prof. Dr. Huseyin Ceylan Pamukkale University)


26.  Wardrop's second principle states: At equilibrium the average
journey time is minimum.
 This implies that each user behaves cooperatively in choosing his own
route to ensure the most efficient use of the whole system.
 •Traffic flows satisfying Wardrop's second principle are generally
deemed "system optimal" (SO).

27.  These characteristics include;
 Ownership
 Functional Classification
 Speed Limit
 Lane Width
 Number of Lanes
 Curb Type
 Pavement Type
 Special Routes (for example, Truck, Snow and Bike
Lane(s))

28. The hierarchy of roads categorizes roads according to their functions and capacities.
 At the top of the hierarchy are limited access roads freeways or motorways, including
most toll roads.
 Arterials are major through roads that are expected to carry large volumes of traffic.
Arterials are often divided into major and minor arterials, and rural and urban arterials.
 Collectors ; collect traffic from local roads, and distribute it to arterials.
 Local roads have the lowest speed limit, and carry low volumes of traffic. In some areas,
these roads may be unpaved

29.  Nearly all roadways are built with devices meant to control
traffic.
 Broadly, these fall into three categories: signs, signals or
pavement markings.
 Their functions is to help the driver navigate, assign the
right-of-way at intersections, indicate laws such as speed
limits and parking regulations, advise of potential hazards,
indicate passing and no passing zones and otherwise deliver
information and to assure traffic is orderly and safe.

30.  This concern the road authorities and highway
infrastructure operators that contribute to safer and
more efficient travel.
 This includes techniques such as traffic incident
detection, incident management, traffic control (urban
and inter-urban), traveller information (pre-trip and on-
trip), public transport priorities, electronic payment and
travel demand management techniques(World Road
Association).

31.  Some of the more important features of road network around the
world have been discussed.
 These include concept, importance, achievement and challenges,
design, characteristics, systems, classifications and hierarchy.
 An outline has also been given on the road network in Nigeria
including its control and operation.
 It is believed that road network is necessary for accessibility by
people and/or motorist from one place to another for security and
socio-economic development.

32.  1. Proceedings of the IEEE ( Volume: 91, Issue: 12, Dec 2003, Page(s): 2043 – 2067.
 2. a b Webb. English Local Government. pp. 157-159.
 3. T.L Ryntathiang, D.D Amar, Rajiv Kumar, G. AppaRoa. Green Road Approach For The Sustainable Development In India,
European Journal Of Sustainable Development.
 4. House of Commons Transport Committee(2010), The major Road Network, Eighth Report of Session 2009–10. England.
 5. Philip Nwosu (December 21, 2007). "Fake Commodore arrested over military outfit". Online Nigeria. Retrieved 2011-06-
23.
 6. Jump up ^ Andrew Airahuobhor (5 August 2010). "Police Can't Ban Merchant Navy - Kemewerigha". The Daily
Independent (Lagos). Retrieved 2011-06-23.
 7. Assoc. Prof. Dr. Ozgur Baskan, Assoc. Prof. Dr. Huseyin Ceylan, Department of Civil Engineering ,Engineering Faculty,
Pamukkale University , Denizli / Turkey.
 8. "Road Transportation – A History and How We Use it Today". American Auto Move. 30 August 2012. Retrieved 12
September 2012.
 9. World Road Association (PIARC/AIPCR),Road Network Operations & Intelligent Transport Systems A guide for
practitioners.
 10. John Van Rijn (2005) Road Network Development & Management, Pp. 9