Even small disruptions in the network caused by traffic restraints or through the failure of parts of the network lead inevitably to large traffic obstructions and in consequence considerable costs for the user and the national economy. It is therefore of far-reaching importance that the maintenance measures are managed using a system which, taking the available funds into account, guarantees that the measures can be taken at an optimal time with regard to both construction and traffic. In order to provide a more objective basis for decisions that were previously made on a subjective basis, a system to rate and evaluate the condition of federal trunk roads in Germany (ZEB) was introduced in 1992. Factors measured include longitudinal evenness, transverse evenness, skid resistance and surface damages. The road network is evaluated every four years. Through a standardised evaluation of condition indicators and the establishment of alert values and threshold values, a sort of requirement level is defined. It is practically impossible to use the mass of data appropriately if it is only stored on a computer or available as a print-out. Therefore tools have been developed which are able to represent the data on plans and maps. The possibilities for depicting the data have met with considerable interest on the part of the road planning administration. On the basis of the ZEB, a national standardised Pavement Management System (PMS) is being developed that can be applied routinely by the Federal States (Lander) in order to reach an optimisation of road maintenance through standardised, economic assessment of maintenance measures. The PMS developed was tested in all of the 13 larger States during the initial application. The users consider the PMS a significant aid to systematic maintenance planning. The PMS results for both sections of network and the overall road network are evaluated as plausible and practical. The initial application of PMS has in some places undergone a smooth transition into regular application, and in initial stages, is even being used routinely. The user now has a tool available that provides assistance for maintenance management and planning through; establishment and rating of the technically possible alternatives for rehabilitation / restoration measures on the project level, creation of a maintenance programme for the respective road network based on the optimised alternatives, rapid implementation of strategic objectives in quality or financial scenarios for parts or the whole of the network.uThe present methods for measuring longitudinal unevenness are reaching their limits. For example, step-like, mostly periodic uneven areas, which primarily appear on older cement road surfaces of the Federal motorways that are often in need of repair, are not sufficiently taken into account by present evaluation techniques. Therefore, the inclusion of not only the geometry but also the effects of longitudinal unevenness in the evaluation and rating concept is called for. The newly developed Longitudinal Unevenness Effect Index (LWI) is based on the assessment of vertical vibration values in the human body, load strain and wheel load fluctuations as a reason for road stress. At present an extended LWI test is being carried out as a preliminary step to its integration into the ZEB assessment concept. The Federal Ministry of Transport, Construction and Housing introduced a new comprehensive body of legislation in 2001 that further pave the way for systematic road maintenance using PMS. This will also provide the opportunity of comparing the results of PMS implementation and maintenance programmes for the 16 German Federal States. In order to continue to meet the needs of the road users in the future, the feasibility of a new type of construction contract - the functional construction contract - is furthermore being tested. The name "functional construction contract" intends to make clear that the function of road construction, that is the safe serviceability and the durability of the roadway, is the focal point of the contract between the administration funding the construction and the contractor who carries it out. The functional construction contract places new construction measures or basic restoration of a road and its structural maintenance over a period of 20 years under a single contract. For the covering abstract see ITRD E135448.
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