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Civil Engineering
Reducing rural isolation:
a tale of two bridges
Westerink and Alonso Barco

Proceedings of the Institution of Civil Engineers
http://dx.doi.org/10.1680/jcien.15.00053
Paper 1500053
Received 20/08/2015
Accepted 22/10/2015
Keywords: bridges/developing countries/footbridges

ICE Publishing: All rights reserved

Reducing rural isolation: a tale of
two bridges
Hendrik Westerink EIT

1

Junior Bridge Designer, Cowi North America, Canada

1

2

Miriam Alonso Barco CEng
Senior Engineer, Flint & Neill, UK

2

Worldwide, more than one billion rural residents do not have all-weather access to markets, schools, healthcare
and other facilities, a condition which significantly impedes economic development. In the developing world,
where walking is the primary form of transportation, footbridges can provide safe year-round access to
these critical facilities by eliminating weather-induced obstructions in the transportation network caused by
flooded rivers. This paper presents case studies of two footbridges constructed with non-profit organisation
‘Bridges to Prosperity’. The 81 m long Rio Abajo footbridge in Nicaragua and the 51 m long Gaseke footbridge
in Rwanda were constructed with industry partners from North America and the UK. The  importance of
engaging with the beneficiary communities when working on humanitarian engineering projects was evident
during the construction of both footbridges. The significant local involvement in the construction of both
footbridges will help to ensure the long-term sustainability of the infrastructure projects.

1. Introduction and project background
Rio Abajo is a 3000-person agricultural community in northern
Nicaragua, 200 km north of the country’s capital city of Managua
as shown in Figure  1. Gaseke is a 2700-person agricultural
community in central Rwanda, 30 km north of the country’s capital
city of Kigali, as shown in Figure 1.
Although separated by thousands of kilometres, the two
communities shared a common challenge: lack of a safe, yearround crossing of a nearby river isolated the communities and
limited their access to local markets, schools, clinics and other
facilities in nearby towns and villages. Both communities recently
celebrated the construction of pedestrian suspension bridges as
part of a ‘Bridges to Prosperity’ (B2P) bridge-building programme.
B2P is a non-profit organisation headquartered in Denver, USA
and includes the Bridges to Prosperity UK Charitable Trust, which
is a recognised charity in the UK. The organisation is committed to
combatting rural isolation by building footbridges with communities
around the world. Since its inception in 2001, the organisation
has helped build more than 170 bridges in Africa, Asia and Latin
America, typically teaming up with university student groups, bridge
engineering and construction professionals and local governments.
The new Rio Abajo footbridge spans 81 m over the Rio Pueblo
Nuevo River and replaces a bridge that was destroyed by Hurricane
Mitch in 1998. The  secondary schools, clinics and government
services closest to Rio Abajo are located in the town of Pueblo
Nuevo, which is approximately 2 km west of Rio Abajo and on

the other side of the Rio Pueblo Nuevo. Before the footbridge was
built, Rio Abajo residents had to swim across the river when it rose
during the rainy season, or alternatively walk to Condega, another
town that is 8 km east of Rio Abajo. Canadian bridge designer
Cowi North America and American contractor Kiewit Bridge &
Marine teamed up to construct the footbridge with local volunteers
in March 2015.
The new Gaseke footbridge over the Mwange River has a 51 m
span and was completed in July 2015. The  Nkoto community
crosses the Mwange River to access infrastructure and weekly
markets in Gaseke and the Gaseke community crosses the river
to access farmland. The  previous river crossing shown in the
foreground of Figure 2 consisted of a single steel beam, which was
dangerous to cross when the water level was high and frequently
washed away during the rainy season, cutting off the Nkoto
community from essential services in Gaseke. At  least 15 people
are known to have lost their lives when attempting to cross this
river. The  communities lobbied for a new bridge for years, but
had trouble securing funding for the project. Flint & Neill, a Cowi
company, and contractor Balfour Beatty joined the B2P programme
to help the Gaseke community construct its footbridge.

2. Rural isolation impedes development
Rural isolation and lack of access to essential services are
significant problems in the developing world. The  World Bank

1

Civil Engineering


Reducing rural isolation: a tale of two bridges
Westerink and Alonso

PROOFS

(a)

(b)

Figure 1. Rio Abajo and Gaseke project locations

estimates that one billion people in low-income countries around
the world do not have access to an all-weather road (World Bank,
2015a). These people are at a disadvantage when compared to
those with road access because education, healthcare and economic
opportunities are often not available year-round, especially in
countries with severe rainy seasons.
Various studies have shown that poverty is more prevalent in
areas with little or no access and that there is a correlation between
gross domestic product (GDP) and the percentage of a population
with all-season access within a few kilometres of a household.
One study in Andhra Pradesh, India investigated three poor rural
districts in which approximately 60% of the roads were not passable
during all seasons. Households with all-weather access averaged
more than double annual household income compared to those
without all-weather access. The female literacy rate in households

Figure 2. Gaseke residents cross the Mwange River on the existing
steel beam during footbridge construction

2

with all-weather access was 60% higher compared to households
without all-weather access (Lebo and Schelling, 2001).
Rural isolation often impedes a community’s economic development.
Studies of communities in Zambia and Burkina Faso show that moving
from subsistence agriculture to a market economy significantly
increases the demand for transport while decreasing poverty. If  allseason access to transport is not available, the market economy suffers
as agricultural goods cannot be delivered before they spoil, making the
transition from subsistence agriculture more difficult (Dennis, 1998).
The World Bank uses a rural access index (RAI) to evaluate the
portion of an area’s rural population that has adequate access to
transport. The RAI is defined as the percentage of a rural population
that lives within 2 km, which corresponds to a 20−25 min walk, of an
all-season road. Occasional disruptions in access for a short duration
during inclement weather are acceptable. RAI  groupings for many
countries are shown in Figure 3. The RAI allows the World Bank to
track trends in rural isolation and focus efforts on areas with a low RAI.
Nicaragua and Rwanda, the sites of the two footbridges discussed
in this paper, both demonstrate a need for improvement of rural

Figure 3. Rural access indices by country (courtesy World Bank Group)

Civil Engineering


Reducing rural isolation: a tale of two bridges
Westerink and Alonso

PROOFS
access. In 2000, the RAI in Nicaragua was 28%: of the country’s
2·3 million rural residents, only 655 000 lived less than 2 km away
from a road with all-season access (Roberts et al., 2006). The need
for improvement of access in rural Rwanda is equally evident.
The  1999 RAI of 52% indicates that 3·5  million rural Rwandans
do not live within 2 km of an all-season road (World Bank, 2015b).

3. Footbridges reduce rural isolation
Walking is the primary form of transportation in many rural areas
in the developing world and footbridges are an important part of
the rural transportation network. Household surveys carried out in
various locations in rural Africa indicate that 87% of trips happen on
foot and a typical adult woman’s effort spent on transportation was
equivalent to carrying a 20 kg load for between 1·4 and 5·3 km every
day (Calvo, 1998). Many people living in rural areas depend on rural
transportation infrastructure to carry out their daily tasks. Lack of
access across flooded rivers is often the main reason why communities
become totally cut off during the rainy season (Dennis, 1998).
Reducing rural isolation and increasing access to services that
promote development are complex processes that involve many
variables and stakeholders. At a general level, rural access solutions
can be evaluated in terms of their effect on proximity of essential
services, mobility of affected individuals, or a combination of both
factors (Edmonds, 1998).
In some cases, the provision of markets, clinics, and schools
for an isolated community is the preferred solution to promote
development. In  other cases, these services are already available
relatively nearby, but rivers that flood significantly during the rainy
season make year-round access difficult or impossible. Footbridges
placed in well-selected locations provide an economical upgrade to
the transportation network in these instances (Dennis, 1998).

4. Project organisation and scope
The Rio Abajo and Gaseke footbridges were constructed as part of
the B2P industry partnership programme, which engages beneficiary
communities in developing countries and bridge professionals
from developed countries to construct footbridges in the isolated
rural communities where they are needed. The  programme allows
companies to contribute to a bridge project by providing financial
support for the organisation’s global bridge-building programme,
conducting a design review, travelling to the bridge site to help the
local community construct the bridge superstructure and providing
feedback on bridge design and field construction processes upon
bridge completion (Bridges to Prosperity, 2015a).
The project teams for both the Rio Abajo and Gaseke footbridges
included a bridge designer and contractor who together worked
with the community to construct the bridge. The  combination of
the contractors’ experience with construction means and methods,
jobsite safety and work planning, and the designers’ experience
with structural design, detailing and quality control proved useful
in successfully completing both bridges.
The bridge constructors and designers joined the Industry
Partnership programme and worked with B2P staff to conduct
design reviews of the structures after being introduced to the
projects. This process allowed the teams to gain an understanding
of the structural details and proposed construction sequence.

Team members gained an appreciation for several details used in
the bridges that are non-standard by typical North American and
European standards because of the relatively low costs of labour
compared to materials in Nicaragua and Rwanda, light pedestrian
loading of the bridges and uncertainty in site conditions.
After the design reviews were complete, B2P staff worked with the
Rio Abajo and Gaseke communities to construct the bridge foundations
and access ramps. The build teams, each composed of between ten and
15 bridge design and construction professionals, travelled to site for two
weeks to work with the community on the construction of the bridge
superstructures. Each project team attended a bridge inauguration
ceremony after the successful completion of the bridge.

5. Footbridge design
The Rio Abajo and Gaseke footbridges closely match the
standard design that B2P uses for its suspension bridges. Structural
components are designed for permanent, pedestrian, livestock and
wind loads using a variety of load combinations. The design live
load on the bridge is based on the 1997 American Association
of State Highway and Transportation Officials (Aashto) Guide
Specification for Design of Pedestrian Bridges (Aashto, 1997)
and is taken as between 320 kg/m and 415 kg/m depending on the
bridge length. The  wooden bridge deck is designed for a 227 kg
point load from a livestock hoof or motorcycle, and the wind load
on the bridge is generally estimated as 40 kg/m.
The main cables of the bridge are designed with a factor of
safety of 3·0 for axial loads from the governing load combination.
All  bridge components made of structural steel are painted and
the wooden bridge deck is coated to extend the service life of the
structure (Bridges to Prosperity, 2015b). A  structure elevation,
cross-section and anchorage elevation for the Rio Abajo footbridge
are shown in Figure 4.
The Rio Abajo footbridge, pictured in Figure 5, spans 81 m over
the Rio Pueblo Nuevo. Bridge users access the 1·2 m wide bridge
deck by way of reinforced concrete and masonry approach ramps
at each abutment. Hand-sawn timber planks on the cable-supported
deck surface, cut from the Nicaraguan tempisque hardwood tree,
span between transverse, double-angle steel floor beams spaced
every metre along the bridge alignment.
Steel bar hangers that are cut and bent on site to control the
deck geometry ensure a minimum freeboard of 3 m above the
known high-water level. The  hangers carry loads from the deck
to the main suspension cables. Each main suspension cable
comprises three sheathed post-tensioning strands that pass over
9 m tall steel pipe towers. The  towers are founded on reinforcedconcrete and masonry pedestals and the cables anchor into an atgrade reinforced-concrete transition block. Cable loads from the
transition block are transferred to a buried deadman anchor block,
which is designed to resist sliding and uplift.
The structural form of the 51 m long Gaseke footbridge over
the Mwange River is very similar to the Rio Abajo footbridge, as
B2P seeks to employ standard bridge designs whenever possible
to streamline training, field construction, bridge inspection and
maintenance. The  bridge, which includes 7 
m tall steel pipe
towers, is scaled down because of the reduced span length and the
foundation arrangement is slightly dissimilar owing to geotechnical
conditions.
3

Civil Engineering


Reducing rural isolation: a tale of two bridges
Westerink and Alonso

PROOFS

Figure 4. Rio Abajo footbridge: (a) elevation; (b) cross-section at midspan;
(c) anchorage elevation. HDPE, high-density polyethylene

Other structural differences are caused by material availability:
the deck planks are cut from a local Rwandan tree and the main
suspension cables utilise steel wire rope that was donated to
B2P and is more readily available than post-tensioning strand in
Rwanda. Other minor structural differences include the size and
grade of steel sections, reinforcing steel and structural bolts.

Figure 5. Steel bar hangers transfer loads from the deck to the main
cables on the Rio Abajo footbridge

4

6. Footbridge construction
The construction of the Rio Abajo and Gaseke footbridges was
completed using a similar construction process. Both bridges were
built mainly using manual labour and processes because of the lack
of construction technology and facilities existing in both areas.
B2P  staff worked with the local community to lay out the bridge
geometry using an automatic level and construct the cast-in-place
concrete foundations and access ramps. After these components
were constructed, scaffolding towers were erected at each abutment.
Guy wires were installed on the scaffolding towers to allow them
to be used to pull the steel pipe towers, which are hinged at their
base, into position. The  scaffolding was then used to temporarily
support the steel pipe towers until the main suspension cables were
installed to the correct elevation and anchored.
The steel bar hanger and floor beam assemblies were installed at
the tower and moved to their correct position using pull cables that
govern the spacing of the hangers along the main suspension cable.
Deck planks were bolted to the floor beam assemblies, starting
at each abutment and working towards the midspan as shown
in Figure  6. Fencing was installed on each side of the bridge to
provide safe access across the river. The bridge was completed by
adding a cast-in-place transition segment to the concrete approach
ramp to match the elevation of the as-built deck planks.
Safety during construction was an important consideration
for both footbridges. Each team promoted a culture of safety by
appointing a safety manager to monitor the work processes and

Civil Engineering


Reducing rural isolation: a tale of two bridges
Westerink and Alonso

PROOFS
ensure all work was being completed safely. Local volunteers from
Rio Abajo and Gaseke donned personal protective equipment,
many for the first time in their lives, to work alongside the build
team. Morning safety briefings were conducted to inform every
worker of the tasks to be performed and their associated risks.
During installation of longitudinal deck planks and fencing, a fall
protection system provided access to the bridge. Both footbridges
were successfully constructed without injuries.

7. Lessons learned

from working alongside bridge professionals will motivate the Rio
Abajo community to maintain and repair the bridge over its life span.
The Gaseke footbridge project also emphasised the importance
of involving the local community in the footbridge construction
project. The  Gaseke community constructed the footbridge
foundations with the assistance of B2P staff before the build team
arrived on site. During the construction of the superstructure, the
community continued to contribute their time and energy to the
footbridge project as shown in Figure 7.
The build team took care to involve the Gaseke volunteers
by translating morning briefing meetings into the Kinyarwanda
language to inform the entire team of the construction goals
for that day. Build team members taught local volunteers
about suspension bridge construction and often learned about
the practical aspects of hands-on labour from the Rwandan
volunteers. Each volunteer was encouraged to contribute to
different aspects of the bridge project instead of merely focusing
on task efficiency and finishing the superstructure quickly.
The  knowledge transferred to the local community will allow
them to maximise the service life of the footbridge by performing
repairs when they are required.

The footbridges constructed in Rio Abajo and Gaseke taught the
project teams valuable lessons about international development
projects. For  many team members, the footbridge projects were
their first exposure to humanitarian engineering. One of the most
important lessons learned was the importance of involving the local
community in the footbridge planning and construction process.
Involving the beneficiaries of the infrastructure project in its
planning and construction is very beneficial as it can help identify
optimal sites for footbridge construction and it creates a sense of
ownership that community members receive from working directly
on the project (Dennis, 1998). Involving the community also
creates local job opportunities, teaches the community volunteers
transferrable practical skills that can be used to find employment
after the project and provides the volunteers with opportunities to
learn about project management and planning (Watermeyer, 1995).
The community of Rio Abajo made a significant contribution
to the footbridge project. More than 150 families donated labour
or supplies to the bridge project, with one volunteer working
for more than 30 d on the bridge foundation and superstructure
construction. The  community was responsible for building the
bridge foundations with help from local B2P staff before the team
of visiting professionals arrived on site.
After the foundations were complete, local volunteers of all ages
worked enthusiastically with the build team during superstructure
construction. Working alongside the build team allowed the
community of Rio Abajo to gain an understanding of what is required
to build and maintain a suspension bridge. The sense of ownership
from contributing directly to the bridge and the knowledge gained

For the developing world’s rural population, lack of access to an
all-weather road is often an impediment to development because
of the difficulty associated with travelling to schools, markets and
healthcare. When water levels rise during rainy seasons, crossing
rivers to access essential services can be dangerous or impossible.
In these situations, footbridges provide an efficient upgrade to the
rural transportation network by removing obstructions caused by
flooded rivers.
The Rio Abajo and Gaseke footbridges provide communities in
Nicaragua and Rwanda with year-round access to essential services
and eliminate dangerous river crossings during rainy seasons.
The  partnerships involving non-profit organisation Bridges to
Prosperity, build teams from North America and the UK and local
volunteers were successful in completing the footbridge projects
safely and efficiently.

Figure 6. Deck planks installed on the Rio Abajo footbridge

Figure 7. Gaseke residents work with the build team to construct the
footbridge towers

8. Conclusion

5

Civil Engineering


Reducing rural isolation: a tale of two bridges
Westerink and Alonso

PROOFS
Beneficiary involvement in humanitarian engineering
infrastructure projects should be maximised to ensure the longterm sustainability of the projects. Local involvement gives the
communities a sense of ownership in the project and teaches them
practical skills that can be used to maintain the infrastructure. This
was evident during the construction of the Rio Abajo and Gaseke
footbridges: contributions from community volunteers were
important during footbridge construction and the skills imparted to
them will help maintain the footbridges to prolong their service life.
The appreciation that the communities of Gaseke and Rio Abajo
have for the new footbridges is evident. Each project concluded with
an inauguration ceremony, which included the first river crossing
using the new bridge as shown in Figure 8 for the Gaseke footbridge
and Figure  9 for the Rio Abajo footbridge. Local politicians,
bridge volunteers and community members gathered for cultural
performances and speeches to celebrate the bridge opening. Both
bridges are now in service and will continue to provide the Rio
Abajo and Gaseke communities with a safe river crossing for years
to come, and in turn, reliable access to the opportunities and services
that will allow families in these communities to thrive.

Figure 8. The Gaseke community crosses the new footbridge for the
first time on opening day

Acknowledgements
The authors would like to acknowledge Cowi North America,
Flint & Neill (a Cowi company), Kiewit Bridge & Marine and
Balfour Beatty for their contributions to the footbridge projects.

References
Aashto (American Association of State Highway and Transportation Officials)
(1997) Guide Specification for Design of Pedestrian Bridges. Aashto,
Washington DC, USA.
Bridges to Prosperity (2015a) http://www.bridgestoprosperity.org/ (accessed
19/11/2015).
Bridges to Prosperity (2015b) http://bridgestoprosperity.org/resources/
technical-resources/ (accessed 19/11/2015).
Calvo CM (1998) Options for Managing and Financing Rural Transport
Infrastructure. The World Bank, Washington, DC, USA, World Bank
Technical Paper No. 411.
Dennis R (1998) Rural Transport and Accessibility: A Synthesis Paper.
International Labour Office, Geneva, Switzerland, Rural Access Technical
Papers (RATP) No. 1.
Edmonds G (1998) Wasted Time: the Price of Poor Access. International Labour
Office, Geneva, Switzerland, Rural Access Technical Papers (RATP) No. 3.
Lebo J and Schelling D (2001) Design and Appraisal of Rural Transport
Infrastructure: Ensuring Basic Access for Rural Communities. The World
Bank, Washington, DC, USA, World Bank Technical Paper No. 496.
Roberts P, Shyam KC and Rastogi C (2006) Rural Access Index: A Key
Development Indicator. The World Bank, Washington, DC, USA, World
Bank Transport Paper TP-10. See http://www.worldbank.org/transport/
transportresults/headline/rural-access/tp-10-final.pdf.
World Bank (2015a) http://www.worldbank.org/en/topic/transport/
overview#1 (accessed 19/11/2015).
World Bank (2015b) http://www.worldbank.org/transport/transportresults/
headline/rural-access/rai-updated-modelbasedscores5-20070305.pdf
(accessed 19/11/2015).
Watermeyer RB (1995) Community based construction: a route to
sustainable development and job creation. Journal of the South African
Institution of Civil Engineering 37(1): 6–10.

6

Figure 9. Schoolchildren cross the Rio Abajo footbridge before the
inauguration ceremony


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