Investment Road Maintenance: Comprehensive Guide to Infrastructure Rehabilitation

Investment road maintenance encompasses: pavement rehabilitation on surfaces where impact holes cover over 15% of the total pavement area or on surfaces where deformation or deterioration of the road construction has occurred, then strengthening the road construction by installing new layers or reprocessing the road construction on heavily deformed surfaces, replacement of damaged drainage systems or landslide remediation, damaged retaining and facing walls, replacement or repair of bridges and structures whose stability is compromised or replacement of temporary structures with permanent ones, raising structures for road protection from snowdrifts, strong winds, etc., improvement of road alignment elements in horizontal and vertical directions (correction of sharp curves, mitigation of sharp grade breaks by installing curves of larger radius, widening of road platform and pavement), protection of road construction from harmful frost effects, etc.

Many of the listed works and investments of the road service are seasonal in nature – they are tied to a specific annual period (snow clearing, grass mowing and shrub cutting, fence painting and artificial structures, whitewashing and spraying of plantings, etc.), while some are performed throughout the entire year. Therefore, there is a division of maintenance works by seasons into the following categories: spring, summer, autumn, and winter maintenance, depending on the specificity of the period and type of work, because before some periods it is necessary to prepare the road for the upcoming period (conservation and protection measures), and in other periods works on rehabilitation (asphalting, repairs, etc.).

Special attention in road maintenance should be devoted to the spring period, considering that due to alternating freezing and thawing effects, as well as large amounts of water – resulting from snow melting – the bearing capacity of the subgrade and the entire road construction is reduced. During this period, it is necessary to repair the resulting impact holes and deformations, even temporarily, to prevent sudden increase in damage, as well as repair frost damage on all parts of artificial structures, along with cleaning and protection from erosion.

Timely measures must be taken for water removal (construction of channels, ditches, ensuring appropriate cross slope of the pavement, embankments and slopes for more efficient and faster water drainage from these surfaces, ensuring a layer to prevent capillary water rise from the underlying layers and subgrade into the subgrade, construction of systems for draining and diverting groundwater from the subgrade, subgrade and slopes or from cut slopes to prevent landslide occurrence, etc.).

Securing the road from harmful water effects is neither simple nor easy work as it requires extensive and detailed geotechnical investigations, geological investigations and knowledge of geological, geomorphological, hydrological and other conditions, and previous experiences with road construction and maintenance show that, despite undertaking all security measures during road design and construction and careful maintenance, full security cannot be achieved regarding road protection against destructive and harmful water effects in all stages of its construction and maintenance.

The road service work on maintenance primarily relates to taking measures for efficient drainage, cleaning ditches, gutters and systems for diverting surface water from the pavement and cut slopes and embankments to obtain necessary slope and prevent water retention in them, as well as for diverting water outside the road right-of-way. Additionally, it is necessary that drainage and groundwater diversion systems are maintained in proper condition so they can perform project-foreseen functions (lowering groundwater level, preventing capillary rise into upper layers and road construction, diverting water from embankments or from the side of pavement and slopes, etc.), as only in this way can the road be considered protected from water and its correctness and durability guaranteed, and road maintenance satisfactory.

Drainage systems for road body drainage in cuts must be inspected more frequently, and in case of any malfunction, measures should be taken to eliminate observed deficiencies and ensure their normal function; occurrences of local settlement and material sliding on slopes are usually signs of some deficiencies in road body drainage and presence of water in it, so they should be identified and eliminated as soon as possible.

A protective layer is laid over it to ensure protection from harmful freezing effects. Pavement repairs without prior rehabilitation and ensuring appropriate protection from harmful frost effects and efficient drainage do not give desired results, as at such locations, due to repeated settlement of unsecured underlying layers, greater irregularities in the pavement are created that prevent the passage of motor vehicles and lead to even greater pavement failures.

In unfavorable periods for maintaining the road construction under traffic, and especially during ice thawing and snow melting, vehicle weight restrictions can be applied until conditions improve, and in extremely unfavorable conditions – if road safety during traffic would be significantly compromised – traffic suspension should be foreseen.

Measures taken will depend on the results of road condition testing (by measuring deflections and visual observation on the most endangered sections or sections that can be considered representative for individual road sections), road construction structure and its sensitivity to the mentioned influences, as well as climatic conditions – namely the duration of the frost effect period; intensity and duration of freezing-thawing cycles.

By temporarily suspending heavy vehicle traffic on endangered road sections, road protection is achieved and time necessary for water drainage from the subgrade or road construction layers and achieving the necessary bearing capacity foreseen by the road project is ensured.

To ensure traffic flow even in unfavorable weather conditions, it is necessary to plan and secure road directions on main and basic traffic routes, safe for traffic even in unfavorable weather conditions, as well as roads that come into consideration as bypass routes for each road on which, considering its characteristics and bearing capacity in unfavorable conditions, traffic suspension may occur.

Investment road maintenance requires comprehensive planning and implementation of various measures to ensure road infrastructure longevity and safety. Seasonal maintenance programs, proper drainage systems, and traffic management during adverse conditions are essential components of effective road maintenance strategies. By implementing these measures, road authorities can ensure optimal performance and extended service life of transportation infrastructure while maintaining safety for all road users.