I recently added two posts about unsuccessful projects for the preparation of new road geometric design standards, one for Kazakhstan and other countries (see here) and one for Kenya (see here).
Updating existing standards, or replacing them by entirely new ones, can be a good idea, as new approaches and values are developed and accepted. This process seems to be under way in Tanzania. The country has a history of what appears to be a fairly stable development of standards. The ones I have found so far are the following:
1989 document – Tanzania Geometric design of roads, Manual (Ref. 5278), produced by the Tanzania Ministry of Works
2011 document – Road Geometric Design Manual (Ref. 294); in detail the text says “the manual has been prepared through the technical co-operation between the Ministry of Works (MOW), the Tanzania National Roads Agency (TANROADS) and the Norwegian Public Roads Administration (NPRA)”.
2016 document – Tanzania LVR Manual (Ref. 5280). Here the text says that “the Manual was developed under the policy direction of a Roads Technical Committee comprising senior representatives from MOWTC, President’s Office-Regional Administration and Local Government (PO-RALG), TANROADS and Road Fund Board (RFB). Technical guidance was provided by a Technical Working Group comprising representatives of the MOWTC, PO-RALG, TANROADS, Local Government Authorities, RFB and the local consulting industry” – and that “The UK Department for International Development (DFID) provided support of the development of the Manual through the African Community Access Programme (AFCAP)”.
2023 document – (Ref. 5275) It looks as if there is now a new manual in development. The International Road Federation website refers to an organisation called gktp which has been working on a Review of the Tanzania Road Geometric Design Manual (2011) and which has recently published a document on the Internet. Information suggests this is intended to lead to a new design manual for Tanzania.
Commentary
Note that two of the documents mentioned involve input from government agencies from other countries (Norway, UK)
One document involves input from a private organisation, an example of similar bodies becoming involved in road design standards in different countries
The 2011 and 2016 documents listed the names of individuals who worked on the preparation of the documents. This seems to be a growing practice. We will probably be able to trace some of these experts as named authors in the preparation of similar documents for other countries, and even to develop a list of “leading authors” of road design standards
A set of historic design standards could be used to see how advice on geometric design and on individual parameters, such as “terrain” and “side friction” have changed over time. This will be also an indication of consistency or plausibility (plausibility as in “where advice has changed, for good reasons”).
References
Ref. 5278 Tanzania Geometric design of roads, Manual 1989
Partial screenshots from the ESCAP iSearch Library, search for “Asian Highway Network”
Introduction
From the UNESCAP website
“The Economic and Social Commission for Asia and the Pacific (ESCAP) is the most inclusive intergovernmental platform in the Asia-Pacific region. The Commission promotes cooperation among its 53 member States and 9 associate members in pursuit of solutions to sustainable development challenges. ESCAP is one of the five regional commissions of the United Nations.”
ESCAP covers 8 topic areas, one of which is Transport. One of the organisation’s transport-related activities is the development of the Asian Highway Network or AHN, (see Wikipedia), a road construction and improvement project covering some 32 countries and around 140,000 km. ESCAP also in 2021 set up a Transport Research and Education Network for its member countries. As such ESCAP and its library should be a good place to look for AHN geometric design standards and other such documents from the region.
The ESCAP website offers a number of “knowledge products”, one of which is the ESCAP library. (These knowledge products, besides the library, seem to include access to various ESCAP and other publications, and to a number of private and commercial resources and/or websites, such as the United Nations digital library and OpenDOAR, which “is the quality-assured global directory of academic open access repositories”.
Library page
The library page says “The United Nations ESCAP Library provides its staff and member States with the knowledge resources they need to meet the Commission’s goals and objectives and advance regional implementation of the 2030 Agenda for Sustainable Development”.
Isearch
Is a search tool which will “search the ESCAP library collection” or, as the iSearch page says, will give access to ESCAP Library’s online and print collections (E-journals, E-books, and full-text articles) and which can also search other UN Libraries.
The iSearch search function will give a list of results which can be filtered by e.g. date, subject, language etc. Clicking on the title of a document in the “found” list takes the user to a more detailed page on the document, which includes a summary paragraph and often a download link (but not “status” info). Isearch also offers registered users the option of saving selected documents to a “favourites” list.
Commentary
The ESCAP website has improved over the last few months, IMO with a better user experience. In some ways it now offers so many services to visitors that it can be overwhelming. It might be worthwhile for ESCAP to develop a dashboard type page and a short user-guide for all of its “knowledge products” (including iSearch). Also, some of the resources provided and / or linked to via the ESCAP website seem to be restricted to members of ESCAP and the UN, or to be commercial services which require payment.
The following comments are related to the iSearch page:
Pro’s
chance to save documents to your own “favourites” collection
document summaries
often, document download links
Con’s
you cannot be sure you have found all the relevant / or available documents
Not clear if the documents found are all still current of if some of them have been superceded
Different standards on road geometric design do not always present the same reasoning or values for any particular design parameter (such as say, side friction, or “type of terrain”). Even within one country, the standards are not necessarily consistent, either over time or at a particular point in time – for example, values for side friction published in 1990 may be different to those published in 2023; or two documents published in 2023 might give different values.
Take the standards available for Afghanistan as a random example. Several documents are available online – the earliest I have found dates from 2005, but very probably there were earlier standards as well. I noticed some differences for the parameter “terrain type”.
As one example, Afghanistan is involved in the Asian Highway Network project and so theoretically subject to the AHN design standards. One AHN document from 2004 (Ref. 5118) describes 4 terrain types. The Afghanistan document Rural Roads Manual version 2 (Ref. 1597) from 2013 gives the same 4 types, although it adds a sub-type for “snow” and “no snow”. And an Afghanistan government document from 2020, Low volume rural roads gudeline and standards volume 2 (Ref. 5232), gives a different set of terrain types in its main text and a further set in its appendix A. (and neither of these two sets seem to be compatible with the AHN set from 2004).
Commentary
The individual documents appear to be quite good; what I want to point out refers to consistency of advice. Perhaps the changes are all part of a natural improvement towards something better. But where documents in one country give different recommendations then the reason for the differences should be explained.
From time to time, new standards are issued for most countries. However it would be helpful if, where they present new values they at least explain why they have been changed.
IMO Afghanistan (and other countries) should maintain an online library of standards on road design, indicating which documents are current and which have been superceded. For historical purposes, even superceded documents may be of interest, as roads used today were often built to design standards published yesterday.
References
1597 Rural Roads Manual version 2, Ministry of Rural Rehabilitation and Development, 2013
5118 Asian Highway / UNESCAP Asian highway treaty, UNESCAP, 2004
5232 Low volume rural roads gudeline and standards volume 2 geometric design and road safety, AfghanistanMinistry of Rural Rehabilitation and Development, 2020
In my last post I referred to the development of documents on road geometric design standards prepared around 2002 for Kazakhstan through an ADB-funded project.The documents produced don’t seem to have been successfully accepted.
In 2022 the UK’s TRL was asked to review the Road and Bridges Design Manual – Part 1A:Geometric Design (2009) prepared for Kenya by international consultants, this time through an EU-funded project. The draft submissions by the consultant, made in 2009, were reviewed by a National Steering Comittee in Kenya but were not adopted. TRL’s 2022 report (Ref. 5259) was somewhat critical of the 2009 documents.
So this looks like two examples of road design standards / manuals, prepared by international consultants, but where the standards were not found good enough.
TRL’s project to look at the Kenya manuals also involved the preparation of new documents. In their detailed notes, the TRL report said “ The next step, for each of the proposed (new manuals), and the SRBC, was to develop an idealized framework of the contents”, and “the Consultant and the TTF undertook a preliminary review exercise to establish a new manual structure and coding system for Kenya”. Theoretically what is good for Kenya could be good for other countries, and the TRL’s new manual structure and coding system could be of interest elsewhere.
The new manuals have not yet been released (July 2023) but are likely to be published shortly.
Commentary
The two examples, of unsuccessful road geometric design standards are a cautionary indication that not all documents which have been published as road geometric design standards, are necessarily good material.
I think it is time that the structure of road geometric design manuals should be changed, but more drastically than the TRL idea, and that manuals should be prepared on a parameter basis.
References
Ref. 5259 Consultancy Services for Review and Updating of Road Design Manuals and Standard Specifications for Kenya Ref. No. KENHA/PCS/342/2021, Draft review report November 2022
In 2002 a technical assistance performance audit report (Ref. 5262) was prepared for the ADB on institutional strengthening and policy support to the road sector in Kazakhstan, the Kyrgyz Republic and Mongolia. One of the ADB projects which the audit report covered was TA 5733-REG: A Review of Road Design and Construction Standards. The standards which this project developed were to be applied in the 3 countries above plus Uzbekistan.
Apparently the project TA-5733 was not entirely satisfactory, as the “design of the RETA was irrelevant as it failed to take account of local conditions and produced only general design and construction standards”, and in terms of implementation “the RETA was inefficient in Kazakhstan and the Kyrgyz Republic where the recommended standards are not in use, and efficient in Mongolia, where the standards are in use with adaptations to meet local climatic conditions…..”
Another remark in the audit report was that “International standards are, however, followed in externally assisted road projects in all three DMCs“. (that is, Kazakhstan, the Kyrgyz Republic and Mongolia).
Commentary
Two comments – perhaps not all published standards are good standards; and I have a problem with the term “international standards”.
A dictionary definition of the word “international” (from Merriam Webster) is that the word means “relating to, or affecting two or more nations) – so if I someone drafts a standard that is accepted by Lichtenstein and San Marino it would qualify as an international standard.
The impliedmeanings of the word “international” as used in the phrase in the source document can suggest that the standards referred to are
applicable to every country in the world
accepted by every country in the world
approved as acceptable and applicable by a majority of the practicing road design engineers in the world
I doubt if any of these are true. Arguably “international standards” as such do not yet exist and I doubt if anyone has judged a particular road geometric design standard to be suitable for every country in the world. There is also the question as to how “an “international standards” incorporate “local conditions” (although I think it’s possible).
The phrase I prefer is “multi-country” standards, which I define as a published document (on road geometric design) which has been accepted for use in more than one country. In this sense,
Various countries have developed documents and manuals on road geometric design which have been used in other countries – for example, India, Australia, the UK etc.
Various organisations have issued geometric design standards specifically meant for use in several countries (such as UNESCAP’s Asian highway design standards)
The TA 5733-REG project arguably did produce a multi-country standard – for the 3 countries plus Uzbekistan. There are probably at least 10 other multi-country standards in use at the moment, which may or may not be of good quality.
I am trying to collect details of these and any “multi-country standards” – if you have suggestions for or information on any such standards, please let me know.
References
Ref. 5262 ADB TPA: REG 2002-16 Technical assistance performance audit report on institutional strengthening and policy support to the road sector in Kazakhstan, Kyrgyz republic, and Mongolia
Besides this blog I am working on documents which take a more in-depth look at some of the parameters and values involved in geometric road design. Some are available for download on Academia and on ResearchGate.
The organisation and numbering of these documents now needs improving, and I recently developed a revised structure with a simpler numbering system and 8 document series.
Partial screenshot from the Bicycle Infrastructure Manuals website
Introduction
The “Bicycle Infrastructure Manuals”website presents a simple (which is meant as a compliment) library of some 500 documents related to the design and implementation of cycling infrastructure. Its “About” page says it is:
“A compendium of bicycle infrastructure manuals to serve as reference for cycling enthusiastic urban planners. Bringing to you cycling practices from all over the world to help get you and your community out of cars and onto bikes. This resource contains all the references – from infrastructure design manuals to cycling master plans to strategy guides – that you’d need to achieve cities with strong bike cultures.”
The team behind the website consists of young (which is also meant as a compliment) engineers and planners from a number of different countries.
The search form is quite straightforward (see screenshot above). You can input a search term and apply filters for location and language, and you can sort the table of results. Clicking on the document in the results list shows a sub-table with a little more information about the document.
The results table includes a download link for each document.
A search of the library using the term “shared” produced hits for documents from the UK and Australia,including “Local Transport Note 1/12 – Shared Use Routes for Pedestrians and Cyclists” (UK 2012). This document is available from the search results as a free download.
Commentary
The library is easy to use, and its web presentation could be used as a model for libraries produced by larger international organisations. I should think there would be a lot of work involved in keeping the library up-to-date. For example, during my visit to the site one search query returned documents which included “Local Transport Note 1/12”) but I later did a Google search and found a newer document – “Local Transport Note 1/20 – Cycle Infrastructure Design” (UK 2020).
The documents in the library were published in a number of different countries and languages, so this website potentially brings them to a wider audience.
The website has a page (in development) which will include “a database of different types of bicycle infrastructure photos from over 500 cities around the world, including examples of good and bad infrastructure”. This appears to be thinking on the lines of some of my own documents (see next blog post).
The website also has a “suggestions” page, with a note asking for an email address “so we can follow up with you” – although I didn’t get any follow-up to my suggestion.
Pro’s
Simple and easy to use
You can generally download the documents, at no charge
Various filter options
Con’s
No document abstracts
No document rating
No “status” indication to show (e.g.) if the document has been superceded
Partial screenshot from using the ADB publications tool to search for documents related to “road design”
Introduction
In my recent post on “Notes on road design standards (3) problems and a possible solution” I referred to a possible future post on document libraries. What I had in mind was a look at some online document collections which are possibly related to road geometric design and standards, and which are accessible by the general public. Here are some notes on ADB libraries.
The ADB (Asian Development Bank) is an international funding agency which: “… was conceived in the early 1960s as a financial institution that would be Asian in character and foster economic growth and cooperation in one of the poorest regions in the world…. (and the) … ADB assists its members, and partners, by providing loans, technical assistance, grants, and equity investments to promote social and economic development”.
Several ADB projects have involved questions on road design standards and road geometric design – see for example the 1997 project TA STU 30523 on a “TA for a review of road design and construction standards in the Central Asian Republics”.
Also, the ADB website refers to knowledge management and says “Today, our knowledge management is guided by Strategy 2030, with a call-to-action for ADB to solidify its role as knowledge solutions provider.” There are links to an ADB knowledge solutions page, a page where you can search for ADB publications, and an ADB library catalogue, which is a “is a gateway to the bibliographic records of the ADB Library’s collection comprised of books, ebooks, serials, and audio-visual materials”.
There is also an “ADB knowledge advisory services center” which I didn’t find a direct link for, so wrote to the ADB asking if the knowledge advisory services center could indicate a simple way to use ADBs knowledge management portfolio of services and webpages – but didnt get an answer.
Quick search
So the ADB has document collections, and these will include documents relevant to road design. The ADB publications search results page includes a number of filters e.g. by year, country, language etc. The ADB library search offers a basic search and advanced search options.
A search of the ADB library using the term “road design” produced several hits, including
Street design : the secret to great cities and towns
ICE manual of highway design and management / edited by Ian D. Walsh
and using the same term the ADB publications search produced
Road Safety Guidelines for the Asian and Pacific Region
The road safety guidelines is available as a free download, Street design costs around 79$ from Amazon, and the ICE manual around 140$. I believe the ADB library may deliver the publications on loan to members (probably only employees of the ADB).
Commentary
I found the ADB “libraries” not easy to find or use, (although the problem may be as much with the user – me) and the search results often expensive to obtain. Perhaps the ADB could issue an “idiot’s guide” to its knowledge solutions, and collate its website offerings in this area (including its online libraries) into a sub-area of its website.
This I think is important, since the ADB appears to want to become a leading provider of “knowledge solutions”, and a main requirement would probably be for (access to) the solutions to be clear and user-friendly. Also, failing to answer enquiries is not helpful towards the dissemination of knowledge (although it’s something which I have myself been guilty of).
There are many different ways presently used to present standards.Traditionally presented as a large document with several hundred pages of notes and data / values, and where you often can’t directly find all the material on the point you are concerned with. It would probably help to structure design standards in a different way, first by type of standard, and then by layout of standard. In terms of type of standard I mean
Textbooks, with extensive explanatory notes
Academic papers, which propose new ideas and approaches, and which are readable
Design standards, structured in terms of concise data on geometric design parameters (side friction, medians etc)
Examples – multi-disciplinary publications with good graphics and short background notes
Glossaries
Checklists
With the exception perhaps of design standards and checklists, and to an extent, this is already happening – although not always successfully.
2 New layout – parameter-based design standards
The graphic at the start of this post is taken from Austroads (ref. 5213). It refers to side friction and in the clip shown has two parts – a set of values, and a section for notes and comments. Geometric information can be presented in short documents with a common layout and each specific to a particular parameter such as side friction, with a section for data, and sections for
Clear definitions (e.g. side friction might refer to truck traffic on wet surfaces of sealed roads with tyres and roads in good condition, with normal temperature….)
Source of data
Notes and comments.
The documents could be stored as an online library of pdf files, maintained by a qualified librarian (see next post on libraries). It would also be useful to have a common glossary of technical terms. Unfortunately, whilst there are a number of glossaries available, they do not always agree with each other (even where they are written in the same language).
3 Problems with standards
The previous post suggested a number of problems, both general and specific to values for a particular geometric parameter. The suggested revised presentation of design details could help:
3.1 General problems
Too many standards Solution: change the way standards are structured and presented- Where there are differences of opinion between say a regional and a national government body, the different opinions can be added to the commentary section or as supplementary notes (see e.g. Ref. 5245). No need for national, regional or local standards.
Standards do not always say the same thing Solution: change the way standards are structured and presented The differences may either be through error or through disagreement. Where the differences are plausible, add them to the commentary section; do not produce a new standard document
Standards are not independent Solution: change the way standards are structured and presented There may be different values for a parameter such as side friction – justified perhaps by local research in e.g. Colombia and Uganda. These could be included in a separate documents (with related notes and commentary).
Standards change with time Solution: change the way standards are structured and presented Present documents in an online library, maintained by a librarian. When a document is changed or superceded, issue change notes / or store a copy of the old document with a “superceded” label on it.
Standards are not laid out in the best format Solution: change the way standards are structured and presented
Standards are written in different languages Solution: change the way standards are structured and presented Shorter, focussed texts are more easily translated
3.2 Problems specific to recommended values for a design parameter
Traceability – problem solved, source of data stated
Completeness – problem solved, all related data either stored in the commentary section or in a document linked to another design parameter
Terminology– problem solved, terms are defined in the notes section
Inconsistency – problem solved, disagreement from other government bodies included in the commentary section
Findability – problem solved for any one design parameter, since all the related values and advice contained in one short document, with the data values at the start of the document
Technical – problem solved, this can be discussed in the commentary section
4 References
5213 Austroads, AGRD Part 3: Geometric Design, 2020
5245 Queensland Australia, RPDM Supplement to Austroads- Edition 2: V3 part 8: Process and Documentation, 2019
I am an international consultant and urban studies engineer with over 30 years of professional experience as a highway and urban traffic engineer working with consultancies and government organisations in Europe, the Middle East, and South-East Asia.
Countries I have worked in include Albania, Denmark, Germany, Holland, Hong Kong, India, Jordan, Kuwait, Libya, P.R.China, Qatar, Romania, Saudi Arabia, Switzerland, Tanzania, UAE, Uganda and the UK.
Comparative Geometrics 