• 1.png
  • 2.png
  • 3.jpg
  • 4.jpg
  • 5.png
  • 6a.png
  • 7.png
  • 8.png
  • 9.png
  • 10.png
  • 11.png
  • 12.JPG
  • 13.png
  • 14.png
  • 15.png

Welcome to Chris Bennett's and Lis Pedersen's web site. If you are looking for information Chris' current work on affordable housing, please visit www.mygbhousing.info. The video below tells the background to Chris' project.


Road Maintenance

Reports on road maintenance.

This study aims to explore the potential of optimization-based maintenance strategies in adapting asphalt pavements to future climate change. Based on a highway network in Jiangsu, China, the impacts of climate change, characterized by global warming and intensified precipitation, on pavement life cycle cost (LCC) and performance were quantitively assessed, and the benefits of maintenance optimization in mitigating climate change impacts were examined. The findings indicate that climate change may increase pavement rutting depth and reduce pavement roughness and skid resistance, while its effect on transverse cracking varies over time. Adjusting the maintenance schedules, but still following the threshold-based approach, would increase the LCC by about 15.5 %∼19.1 %. The optimization-based maintenance decision-making model significantly mitigates climate change impacts, ultimately even saving 0.6 % of LCCs compared to the baseline. The outcomes will provide a quantitative understanding of the climate change impacts on asphalt pavements, as well as adaptive maintenance strategies to improve pavement resilience.

2014 - USA - Pavement Preservation Guidelines
 4.12 MB

This report presents a summary of pavement preservation activities and recommended uses, expected longevity, and expected pavement life extension. It also includes some basic information intended to be used by those less familiar with pavement preservation, pavement management, life cycle cost analysis, cost estimating, contracting methods and others to help inform and educate in this important aspect of pavement engineering. Tools and techniques are presented to assist local agency engineers in evaluating costs, benefits, timing, longevity, and the decision-making process for developing an effective pavement preservation program on an individual pavement segment or over an entire network. The report includes examples using real pavement engineering data from several cities and counties in Minnesota to demonstrate topics such as activity timing and the benefits of a preventive maintenance plan rather than a reactive one. A set of guidelines was developed as part of the associated project intended to serve as  reference material and as a training program.

2014 - NZ - Optimizing Drainage Maintenance
 4.08 MB

This project was designed to investigate the importance of drainage maintenance for pavement performance and to recommend a maintenance strategy. With restrained funding for pavement renewals drainage maintenance is a cost-effective method to ensure optimum pavement performance.

A combination of repeated load triaxial testing and modelling of water movement has shown that once water has infiltrated the basecourse it can take weeks for the water content to return to its equilibrium condition. During this time significant damage can take place and there is a high probability that further rainfall will occur and thus re-saturate the pavement.

A drainage risk rating score card was developed and it is recommended that this be adopted by road controlling authorities.

2014 - Australia - Good Practice Resealing Guideline
 1.95 MB

This report provides asset managers with practical guidance in the development and delivery of effective resealing programs. It builds on accumulated experience of previous studies and a review of sprayed seal performance throughout Australasia.

While an extensive body of sprayed seal knowledge and experience exists, there are significant issues which have serious consequences for the state and sustainability of road surfacings, and pavement assets, and ultimately their safe and efficient use.  Examples of good practice do exist and road agencies are encouraged to review their procedures and the capabilities of their systems and human resources, with a view to adopting good practice and building capability.

2013 - USA - Effect of Night Time Paving on Roughness
 1.68 MB

The relationship between nighttime construction scheduling and future road quality in terms of roughness was investigated. Research was three-phased: interviews with local leaders in paving, on-site observations, and historical data analyses. Interviews and on-site observations served to explore potential differences in the paving practices and general opinions in the paving industry regarding daytime versus nighttime paving, while the bulk of empirical research took place in the historical data analyses. Differences in road quality, defined as pavement roughness in this study, between day-scheduled construction and night-scheduled construction were determined by an analysis of the International Roughness Index over the pavement lifecycle as made available to researchers by the Alabama Department of Transportation. Results showed that the roughness values of pavements laid at night were significantly higher than those of pavements laid in the day. Analyzed in 3, 30-month intervals beginning at project completion, night and day roughness values were equal in the first interval, but differences in means and variances expanded in the second and third intervals, with increasing significance over time. Researchers believe the increasing gap over time could be the result of initial night-time construction conditions lack of inspector involvement, low illumination levels and poor visibility, and worker fatigue, with inspection problems being most detrimental.

2010 - USA - Lifespan of Surface Maintenance Treatments
 1.14 MB

Study which prepared a synthesis to highlight the degree to which pavement preservation treatments (including minor rehabilitation treatments) extend the service life of pavements with or without adding strength. This study was carried out by conducting a study of six target states that were known to perform, collectively, the totality of all treatments under

The results of this study are summarized in a series of tables documenting the data provided by the states. A summary of each treatment’s performance is also contained in this report. A series of observations, conclusions, and recommendations are also included. The findings of this activity will be used to provide support for FHWA policy guidance related to pavement maintenance and minor rehabilitation, commonly referred to as pavement preservation.

2007 - Vietnam - Pavement Maintenance Manual
 760.38 KB

These guidelines provide within a single document, recommendations and material for potential inclusion in future editions of the national maintenance handbooks regarding:

• Maintenance procedures for an agreed list of paving types,

• Draft Cost Norms to cover the above procedures,

• Clear illustrated step-by step descriptions of maintenance procedures,

• Advice and comment on the links between condition monitoring and consequent maintenance programmes.

2005 - Romania - Low Volume Road Maintenance Manual
 991.08 KB

The aim of this manual is to provide basic advice for engineers and other technical staff working at commune and village level on how to maintain roads. It had been designed to be used by those with some technical background but with little formal training in road engineering.

2005 - Mozambique - Rural Road Maintenance
 842.39 KB

Report describing area wide road maintenance in Mozambique.

2003 - USA - Contracting for Road and Highway Maintenance
 380.66 KB

This how-to guide offers a distillation of lessons learned and best practices in highway and road maintenance outsourcing to help governments stretch tax dollars by taking advantage of private sector efficiencies and management approaches that can reduce costs and improve the quality of service.

Overseas Road Note 2. This Note describes the principal techniques that will be used to maintain roads within a District in a developing country. Particular attention is paid to the planning and design aspects of the work, as it is in this area that the Engineer will make the largest contribution. Practical execution is not described in detail.


Chris in the NCT Race 

Chris has an adventurous spirit which generally involves cycling, running, or just being out there having a good time. Read his 'Race Reports' below. This is a link to his SPOT GPS tracker. If you are interested in his 'geeky' sport technical blog it is at www.tri-duffer.com. He also has stories of his life as 'An Overtravelled Engineer Working for the World Bank' at World Bank Traveller.


Race Reports


Document Library


  • Chris' published papers and reports are here.
  • His Technical Library  has a range of reports 
  • Golden Bay community projects are here.
  • The history of the ROMDAS company is here.
  • The 'Road to Good Health' HIV/AIDs Toolkit is here.


Technical Library

Chris and Lis

Chris and Lis

We are Lis Pedersen and Chris Bennett. We’ve been married over 30 years and each found our way to New Zealand in the early 1980s from Denmark and Canada respectively. Golden Bay has been our happy place for almost 20 years and we are now based in Pohara just above the beach, with our two cats Coco and Max. 




Read More