Buried utilities (e.g. gas, water, electricity, drainage), many installed decades ago, are vital urban support systems. Their locations are often not well documented, yet accurate location greatly helps replacement, rehabilitation and maintenance of existing services and is crucial for installation of new utilities: it minimises utility strikes / third party damage and the huge associated costs of delayed / additional streetworks. Several international standards and specifications aim to provide guidance on utility surveys to increase client confidence in their accuracy and repeatability. The most recent specification is PAS (Publicly Available Specification) 128 in the UK for underground utility detection, verification and location. This paper investigates the impact of PAS128 by comparing trial site survey results from different utility survey specialists with each other and with the vertical and horizontal accuracies at trial excavations. While the overall detection level was very good for all companies, the research revealed that the definition of quality level QLB1 needs to be reconsidered as it was not achieved in many places with respect to the vertical accuracy. It is recommended that future revisions of PAS128 differentiate between accuracy and confidence since detection by multiple sensing technologies increases the confidence, but not the accuracy as suggested by PAS128.

中文翻译：

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改进的地下公用事业资产管理–评估英国公用事业调查标准（PAS128）的影响

数十年前已安装的地下公用设施（例如天然气，水，电，排水）是至关重要的城市支持系统。它们的位置通常没有充分的文件记录，但是准确的位置可以极大地帮助更换，修复和维护现有服务，并且对于安装新的公用事业至关重要：它可以最大程度地减少公用事业罢工/第三方损失以及延迟/额外的街道工程的巨额相关费用。一些国际标准和规范旨在为公用事业调查提供指导，以提高客户对其准确性和可重复性的信心。最新规范是英国的PAS（公共可用规范）128，用于地下公用设施的检测，验证和定位。本文通过比较不同公用事业调查专家的试验现场调查结果以及试验开挖时的垂直和水平精度，来研究PAS128的影响。尽管总体检测水平对所有公司都非常好，但研究表明，质量水平QLB1的定义需要重新考虑，因为在垂直精度方面很多地方都没有实现。建议将来对PAS128进行修订，以区分准确性和置信度，因为通过多种传感技术进行检测可以提高置信度，但不能提高PAS128建议的准确性。研究表明，质量等级QLB1的定义需要重新考虑，因为在垂直精度方面很多地方都没有实现。建议将来对PAS128进行修订，以区分准确性和置信度，因为通过多种传感技术进行检测可以提高置信度，但不能提高PAS128建议的准确性。研究表明，质量等级QLB1的定义需要重新考虑，因为在垂直精度方面很多地方都没有实现。建议将来对PAS128进行修订，以区分准确性和置信度，因为通过多种传感技术进行检测可以提高置信度，但不能提高PAS128建议的准确性。