Ride Quality Due to Road Surface Irregularities: Comparison of Different Methods Applied on a Set of Real Road Profiles

Abstract

Road roughness evaluation can be carried out using different approaches. Among these, the assessment of ride quality level perceived by road users is one of the most-used. In this sense, different evaluation methods have been developed in order to link the level of irregularities present on road surface profiles with the induced detrimental effects in terms of discomfort. In particular, relationships between wavelength content of road profiles and consequent level of comfort perceived had been investigated by using, in general, a mean panel ratings approach. In this paper, four ride quality evaluation methods (Ride Number, Michigan Ride Quality Index (RQI), Minnesota Ride Quality Index and frequency-weighted vertical acceleration, a wz , according to ISO 2631 were applied to a set of real road profiles. The obtained results were analyzed, investigating a possible relation between the different indices, comparing them also with the most-used road roughness method worldwide: the International Roughness Index (IRI). The analyses carried out in this work have highlighted how the various rating scales may lead to a different ride quality assessment of the same road pavements. Furthermore, comparing the a wz with the values obtained for the other three methods, it was found that their rating scales are set for speeds within the range 80-100 km/h. For this reason, it is necessary to identify new thresholds to be applied for lower speeds, as in the case of urban roads. In this sense, the use of the ISO 2631 approach would seem to be a useful tool.

Raised Pedestrian Crossings: Analysis of Their Characteristics on a Road Network and Geometric Sizing Proposal

“…where W k,I are the frequency weightings in one-third octave bands for seated position, provided by the standards, and a iz is the vertical RMS acceleration for the i-th one-third octave band. This method ( Figure 3) allowed the evaluation of the vertical accelerations in order to analyze the comfort of car passengers [39,45,46].…”

Assessing pavement conditions and their effect on road safety: Ontario experience

“…Driving is a very involved process that heavily relies on the driver's competence behind the wheel (AASHTO, 2010b). Drivers are also heavily influenced by their surroundings (Hauer, 2000), including the discomfort due to vibrations as a result of a rough road surface (Loprencipe & Zoccali, 2017). Road roughness has been linked to increase stress in vehicle structures, increase in the dynamic loads applied to pavement structures accelerating fatigue damage, and decrease in road vehicle-interactions such as steering and braking (Sayers & Karamihas, 1998).…”

Research on the International Roughness Index Threshold of Road Rehabilitation in Metropolitan Areas: A Case Study in Taipei City

“…However, the IRI thresholds used around the world vary widely [16]. This is mainly because the IRI limit value depends on the following aspects: road surface type (i.e., flexible or rigid road surface), road function category, average annual daily flow (AADT), legal speed limit, and the length of the road section considered in the IRI calculation [31]. In addition, their changes depend on new roads or the reconstruction of roads that are still in use.…”

“…In addition, their changes depend on new roads or the reconstruction of roads that are still in use. Among the different parameters that affect the IRI specifications, the most important is undoubtedly the maximum allowable driving speed on the road, the roughness level of which should be evaluated [31]. In view of this, some researchers proposed speed-related IRI thresholds to evaluate the ride quality [32,33].…”