Traffic Highway Research Articles

Design of Concrete Slabs with Optimized Geometry and Built-in Curling Effect on Performance

A new methodology called TCP “Thin Concrete Pavements” has been developed to design the concrete slab thickness by optimizing the slab size given the geometry of the truck axles. The key principle of the design method is to configure the slab size so that not more than one set of wheels are on any given slab at any time, thereby minimizing the critical top tensile stress. Full-scale test sections were constructed and tested at Illinois under accelerated pavement loading conditions with concrete thickness of 8, 15, and 20 cm on both an aggregate (Subbase CBR 4% and 15 cm granular base) and asphalt base layer. Concrete slabs 8 cm thick on a 15 cm granular base withstood 75.000 ESALS, Slabs with 15 cm thickness showed cracks initiating at 12 million ESALs on average. The 20 cm slab thickness showed no fatigue cracking. A Mechanistic-based software, “OptiPave”, has been developed. The new methodology designs slabs that are on average 7 cm thinner than traditional pavements, AASHTO (1993), for the same traffic, with a thickness range of 8 cm to 20 cm thick. This new solution for designing concrete pavements has been used to build roads from local streets to high traffic highways and gives an alternative to asphalt in low volume roads and competes directly in direct cost Thickness design in Chile is very sensitive to climate variables. The AASHTO 93 method doesn’t consider built in curling conditions, which is especially sensitive to construction standards, making this design variable (BIC) extremely important in terms of pavement performance. Two cases are studied in this paper to show the benefits of the optimized designed slabs, in terms of thickness and sensitivity to climate conditions.

Water Quality and the First-Flush Effect in Roof-Based Rainwater Harvesting, Part I: Water Quality and Soil Accumulation

Rainfall runoff may be captured and stored for later use, but the quality of this water can be detrimental in some uses without the use of appropriately designed first-flush diverters. The rainfall runoff water quality was measured on nineteen new small-scale and two aged commercial roofs located near high traffic highways. Roof coverings included asphalt shingles, sheet metal, clay tiles, and tar and gravel. Runoff samples were evaluated for polycyclic aromatic hydrocarbons (PAHs), phosphorus flame retardants (PFRs), and pyrethroid insecticides. Eighteen small-scale roofs were subjected to a range of simulated rainfall events, while natural runoff was sampled on the commercial roofs and one small-scale roof. Runoff was analyzed for pH, conductivity, turbidity, total suspended solids, boron, iron, copper, zinc, manganese, sodium adsorption ratio, nitrate-nitrogen, seventeen PAHs, tris(2-chloroethyl) phosphate, tris(1,3-dichloro-2-propyl)phosphate, bifenthrin, cypermethrin, and lambda-cyhalothrin. Samples from four natural storm events were also analyzed for total coliforms and Escherichia coli. In addition, soils below seventeen existing gutter downspouts were sampled to determine long-term pollutant accumulation. Atmospheric deposition was the main contributor of pollutants in the roof runoff. A majority of samples fell within the U.S. EPA guidelines for non-potable urban and agricultural water reuse. Trace levels of PAHs, PFRs, and insecticides were detected, but all detections were three orders of magnitude below the USGS health-based screening level benchmark concentrations. Results indicate that diverting the first flush, based on turbidity, total suspended solids, or conductivity, can improve the overall water quality and reduce the concentrations of PAHs in harvested rainwater. Downspout soil sampling showed potential for the long-term accumulation of PAHs at concentrations exceeding the minimum human-health risk-based screening levels at these high runoff-loading locations.

Effects of proximity to highways on tissue properties of three tropical grazing grass species

To obtain indicative, extreme scenario data on the possible impacts of expanding road networks in rangelands, this study examined aboveground tissue of three grazing grasses near four high traffic highways: Digitaria eriantha, Brachiaria nigropedata, and Eragrostis lehmanniana. Samples were collected monthly on three occasions at the same respective locations during the rainy season, in transects approximately perpendicular to the highways. For comparison, tissue samples were concurrently collected from a control site more than 3 km from a road. In the laboratory, a whole stem of each specimen was washed in a fixed volume of distilled water. The pH and electrical conductivity of the water containing the washed-off tissue surface material were then measured. Concentrations of heavy metals in dry tissue were determined using ICP-MS analysis. The results showed poorer grass quality near roads. Tissue surface pH was lower (acidic), and electrical conductivity higher, towards the roads. Rainfall tended to dilute the effects. Linear regression models of tissue surface pH and conductivity against distance showed that the effects were pronounced within at least 70 m and up to nearly 800 m from the road edge. The highly nutritious grasses seemed to present higher potential risk of road-sourced metal toxicity to grazers.

Evaluation of recycled asphalt mixtures with different RAP contents and the effect of recycling agent

This research evaluated recycled asphalt mixtures (RAMs) for application as wearing course in heavy traffic highways. The main objectives were to investigate the effect of different RAP contents and the effect of a recycling agent (RA) on the mechanical properties of RAMs. Recycled asphalt mixtures with low (10, 20 and 25%) and high (35, 50 and 65%) RAP contents were evaluated. Two of these mixtures (25 and 50% RAP content) were also evaluated after the addition of the RA. The results indicate that conditioning the RAP during the production of RAMs influences the RAP binder activation and the mechanical behaviour of the mixtures. RAMs with high RAP contents presented better resistance to permanent deformation and resulted in satisfactory resistance to fatigue cracking due to the activation of the RAP asphalt binder. Finally, the addition of the RA improved fatigue resistance for higher amounts of RAP without reducing rutting resistance.

Noise Pollution Analysis Using Geographic Information System, Agglomerative Hierarchical Clustering and Principal Component Analysis in Urban Sustainability (Case Study: Tehran)

In this study, a new approach has been used with SPSS and MATLAB analysis to study urban road traffic noise distribution mapping, to obtain the representative road traffic noise maps. The observation has been performed at a high traffic highway. The factors influencing noise level (traffic, road width, slope, and residential or administrative–commercial land) use were surveyed and recorded for each point and their local and time dependencies were computed. According to the analysis, the maximum value of goodness of fit index for the traffic and noise level relationship was 0.64, followed by 0.489 for the percentage of residential land use. The result of this study showed that the vehicle speed, width of the road, and the land use can affect different sound levels emitted by moving vehicles on road. The model predicts that by increasing one vehicle per hour, an increase in noise level by 0.002 dB will happen.

Multiple Optimization of Cold Reclaimed Asphalt Pavement Mixture

Many asphalt pavements fail structurally after having performed well for some years. In China, when low volume of traffic highway is recycled, the asphalt surface course and the base course stabilized by inorganic stabilizers are sometimes recycled and mixed together to form a new base. Portland cement, lime-fly ash, lime or Portland cement-fly ash is added to improve the strength of the new base, but they are not used at the same time, so it is difficult for a road engineer to select an effective and economical stabilizer. To evaluate the effect and economical efficiency of different stabilizers comprehensively, this paper used Portland cement, lime-fly ash, lime and Portland cement-fly ash to form four kinds of cold recycled mixtures and every kind of cold recycled mixture has 3 mix proportions. The unconfined compression strength, flexural tensile strength, splitting strength, compression resilient modulus, shrinkage performance, water stability performance, fatigue failure and engineering cost of 12 cold recycled mixtures were compared. Finally, the Portland cement-fly ash stabilized mixture with proportion of 5:15:80 was recommended.

Appraisal of Heavy Metals Accumulation, Physiological Response, and Human Health Risks of Five Crop Species Grown at Various Distances from Traffic Highway

Road surfaces and vehicular traffic contribute to heavy metals (HM) contamination of soil and plants, which poses various health risks to humans by entering the food chain. It is imperative to evaluate the status of contamination with HM and associated health risks in soils and plants, especially food crops. In this regard, five crop species, i.e., strawberry (Fragaria ananassa), wheat (Triticum aestivum), tomato (Lycopersicon esculentum), sugar cane (Saccharum officinarum), and tobacco (Nicotiana tabacum), were evaluated at 0–10, 10–50, and 50–100 m distance from the highway near the urban area (Takht Bhai) of Mardan, Khyber Pakhtunkhwa, Pakistan. Lead (Pb) and cadmium (Cd) accumulation, phenolics, carotenoids, chlorophyll, and proline contents in plant parts were assessed. Pb and Cd in plants decreased with an increase in distance. Pb was above the critical limit in all plants except wheat, Cd exceeded the permissible level of the World Health Organization in all plants except wheat and tomato. Pb and Cd were higher in strawberries. Tomato and strawberry fruits, tobacco leaves, and sugarcane stems showed higher Pb contents at a 0–10 m distance. Phenolic contents in leaves were higher than in roots. The target hazard quotient (THQ) in edible parts of most crops has been greater than one, which presents a threat to human health upon consumption. To the best of our knowledge, this study presents the first holistic approach to assess metal contamination in the selected area, its accumulation in field-grown edible crops, and associated health risk.

Discussion on Technical Management of Traffic Highway Construction

Discussion on Technical Management of Traffic Highway Construction

Stage-by-stage control effect field analysis of steel material servo enhanced support system on lateral displacement and bending moment during deep basement excavation

This study enumerates the stage-by-stage usefulness of the addition of a servo system to the lateral steel support system to improve the lateral load resistance of steel support members on an actual deep excavation site. A field case is found in a project of Triumph Unit building block, where a 14.20 m basement is constructed near the existing high traffic highway and high-rise buildings. It is therefore important to choose an appropriate excavation pit lateral support system to ensure the safety during excavation. At the field site, the basement execution works are divided into 5 construction stages. The excavated pit wall displacement and bending moment caused by excavation process are controlled using the steel material servo combined load support at each respective construction stage. The results from field work authenticate the steel servo enhanced support system application on an actual basement construction site. With the application of steel servo enhanced axial loading capacities, the excavated pit induced lateral displacement and bending moment are effectively restrained within the project acceptable alert limits. Moreover, the obtained field results correlate well with previous and current numerical literature data. This study provides a unique chance to advance the steel material servo enhanced support system application to actual deep basement projects with acceptable displacement and bending moment control requirements.

Time-Varying Optimization of LTI Systems Via Projected Primal-Dual Gradient Flows

This paper investigates the problem of regulating in real time a linear dynamical system to the solution trajectory of a time-varying constrained convex optimization problem. The proposed feedback controller is based on an adaptation of the saddle-flow dynamics, modified to take into account projections on constraint sets and output-feedback from the plant. We derive sufficient conditions on the tunable parameters of the controller (inherently related to the time-scale separation between plant and controller dynamics) to guarantee exponential and input-to-state stability of the closed-loop system. The analysis is tailored to the case of time-varying strongly convex cost functions and polytopic output constraints. The theoretical results are further validated in a ramp metering control problem in a network of traffic highways.

Research on Information Management of Traffic Highway Construction Safety Based on BIM Technology

The construction of traffic highway includes design, construction and operation management, which involves a variety of data and information in these processes, while the traditional highway engineering progress is shown in the form of statistical tables, charts and reports, which is difficult to be directly linked with the specific location and pile number of the project and directly displayed. BIM model provides visual project construction management in the overall planning, design, progress and other aspects. At the same time, when the project is completed, this management information will also provide important data information for the use and operation of the highway. In this paper, the application of BIM Technology in highway construction management is investigated in the form of questionnaire survey and on-site interview, which comprehensively reflects the actual situation of BIM application in highway engineering. According to the actual situation, the future BIM Technology will provide good technical support for the informatization of construction industry, which can effectively promote safe construction.

Runoff of the Tire-Wear Compound, Hexamethoxymethyl-Melamine into Urban Watersheds.

Hexamethoxymethyl-melamine (HMMM) is used as a crosslinking agent in resins and plastics and in the manufacture of tires. In the present study, surface water samples were collected from two rivers adjacent to high traffic highways in the Greater Toronto Area in Ontario, Canada. Composite samples collected from the Don River and Highland Creek during rain events and a period of rapid snowmelt were preconcentrated using solid phase extraction and analyzed using liquid chromatography with high-resolution mass spectrometry. Elevated concentrations (> 1 µg/L) of HMMM were detected in surface waters during rain events in October of 2019 and during snow melt in early March of 2020. There were lower average concentrations of HMMM detected during rain events in the winter and spring of 2020. Temporal profiles of changes in the concentrations of HMMM in composite samples collected every 3 h during a rain event in October 2019 closely corresponded to the hydrograph profiles at the sampling sites, with the HMMM concentrations peaking > 6 h after the peak in water levels. This work contributes to the literature showing that HMMM is a ubiquitous contaminant of urban watersheds and that runoff from roads is a vector for the transport of this compound into urban surface waters.Supplementary InformationThe online version of this article (10.1007/s00244-021-00815-5) contains supplementary material, which is available to authorized users.

ACCUMULATION OF LEAD, CADMIUM AND SULPHUR IN PASTURE GRASSES GROWING ALONG TRAFFIC HIGHWAY AND INDUSTRIAL LAYOUT IN SOUTH EASTERN NIGERIA

Possible uptake of lead, cadmium and sulphur by ruminants from three pasture grasses, Penisetum purpureum, Panicum repens and Cynodom dactylon growing along traffic highway and industrial estate in Akwa Ibom state was investigated. Concentration of the heavy metals and sulphur in the grasses were determined by atomic absorption spectroscopy and colorimetric methods respectively. P. repens from the traffic highway contained the highest amount of lead (56.5µg g-1) and sulphur (681 ppm dry weight) which were significantly (p<0.05) higher than those from industrial layout (36.45µg g-1, Pb and 545 ppm sulphur respectively). The highest content of cadmium (1.6µg g1) was obtained from P. repens and C. dactylon from the same location of the traffic highway. The concentration of the contaminants in all the grasses from industrial layout and traffic highway were higher (p<0.05) than those from arable farm land and rural village which made up the control treatment. The results provide reliable information on the possible dangers ruminant animals are exposed to by grazing forages along traffic highways and around industries.

A question of addressing the real issues of the Nigerian Police operatives’ ineffectiveness for improved petormance

The Nigerian Police ineffectiveness in internal security services is a national challenge. The police have been labelled unfriendly and discredited by many due to their personal experiences and media reports. Research findings indicate that with the police, Nigerians are among the worst Police victims of human rights violations in Africa, due to corruption, unlawful and prolonged detention without trials and various unprofessional conduct. This investigation explores the issues of the Nigerian Police road traffic operatives along a heavy traffic highway in North Central Nigeria that qualify their unprofessional attitudes and behaviors, with possible insights to advance knowledge for policies towards improving service delivery. We collected data from police officers of two police formations in the research area, by quantitative survey. Also from the same two locations and another location, we collected qualitative data by applying in-depth analyses of opinion leaders. We applied Herzberg’s two factor theory and observed that lack of both motivators and hygiene factors seem to be impacting the operatives negatively hence they are not motivated to operate effectively. Data suggest that the Police immediate constraints are mainly hygiene factors (monetary rewards, welfare, tools, among others) which build up frustration and predispose them to oppression and extortion of road users, reflecting the overarching corrupt environment. The results support some earlier findings that both motivators and hygiene factors, not mainly motivators, drive employee motivation and performance. Policy implications include enhanced statutory spending and overhaul of the agency structure for improved employee performance.

Airborne phthalates in indoor environment: Partition state and influential built environmental conditions

Exposure to phthalates has recently become a major public health concern. The information of indoor airborne phthalates and their air-particle partition in real indoor environmental condition is still limited. In this study, the gas- and PM2.5-concentrations of 7 phthalates in 40 residences were concurrently measured in summer and winter. The major phthalates (median concentration in the summer and winter, respectively) in indoor air were DMP (2442.3 and 2403.4 ng/m3), DiBP (801.0 and 640.0 ng/m3) and DnBP (5173.2 and 1379.6 ng/m3), whereas the major phthalates in PM2.5 were DiBP (1055.1 and 585.9 ng/m3) and DnBP (1658.5 and 1517.0 ng/m3) and DEHP (215.1 and 344.9 ng/m3). Air-PM2.5 partition coefficients (Kp) of DiBP, DnBP and DEHP were calculated: the summer and winter median values (m3/μg) were 0.053 and 0.011 for DiBP, 0.010 and 0.004 for DnBP, 0.021 and 0.025 for DEHP, respectively. Air-PM2.5 partition of DiBP and DnBP approached equilibrium, while that of DEHP did not reach equilibrium in either season. The impacts of built environmental conditions on phthalate concentrations were characterized. Elevated temperature resulted in accumulation of airborne phthalates. Higher air humidity led to more water absorption of aerosols in summer, facilitated mass transfer of phthalates from air to PM2.5, and resulted in greater Kp of DiBP and DnBP in the summer. Any factors such as proximity to local traffic highway and indoor smoking activities, which can increase indoor PM2.5 concentrations, resulted in significantly higher airborne phthalate concentrations. Improving ventilation was not an effective measure to reduce indoor airborne phthalate concentrations.

Elemental Characterization of Aerosols in Wet Deposition along a Dense Traffic Highway in Ogbomoso, Nigeria

Elemental Characterization of Aerosols in Wet Deposition along a Dense Traffic Highway in Ogbomoso, Nigeria

Nonlinear regression model for predicting environmental traffic noise

Transport is an essential activity for urban life and for the economy, however, bad planning of the city script causes some movement in some places, causing excessive noise levels generated by road traffic. We aim to present a mathematical model that represents the relationship between the equivalent level of sound and vehicle volume quantities using the nonlinear logistic regression model in order to facilitate decision-making in relation to urban planning. We collected the data of sound pressure and vehicle volume for ten days during five hours totaling a collection of 50 hours, with a total of 180 thousand data of sound pressure level. The place of data collection is a highway that passes through the city of Maringa, in Parana, being an intense traffic highway. The results show the performance of the proposed model were differences between measured and predicted traffic noise levels ranged from -0.3 dB (A) to +0.3 dB (A) and the mean difference was -0.006 dB (A). The proposed road traffic noise forecasting model can be used as a decision support tool in urban planning, considering the same boundary conditions as the road study.

Suitability of coal bottom ash and carbonized rice husk in hot mix asphalt

The suitability of carbonized rice husk (CRH) as a bitumen modifier and coal bottom ash (CBA) as fine aggregate in hot mix asphalt (HMA) was investigated in terms of three modifications. First, Marshall properties of HMA specimens with CRH-modified bitumen with 5%, 10%, and 15% of the weight of bitumen replaced with CRH were evaluated. The optimum CRH replacement rate that showed the highest Marshall stability and the lowest bitumen content was 11%. Second, fine aggregate was partially replaced with 3%, 6%, 9%, and 12% CBA. It was determined that 9% of CBA replacement HMA produced the highest Marshall stability at the lowest binder content. Third, both presented modifications applied simultaneously in HMA containing 6% CBA and 11% CRH-modified bitumen showed optimum results with a 1.7% drop in Marshall stability compared with the control mix, which is still within the specified range for medium volume traffic highways.

Cold Recycled Asphalt Mixture using 100% RAP with Emulsified Asphalt‐Recycling Agent as a New Pavement Base Course

The rehabilitation process of asphalt pavements using the technique of milling and filling can cause several environmental problems due to either the disposal of the milled asphalt mix or the exploration of natural resources. One alternative to mitigate these impacts is to reuse this milled material, known as reclaimed asphalt pavement (RAP), in the construction of new pavement layers. Within the several available techniques to reuse the RAP, cold recycling using an emulsified asphalt‐recycling agent has shown great potential. The aim of this study is to evaluate the application of a cold recycled asphalt mix using 100% RAP with an emulsified asphalt‐recycling agent as a new pavement base course. A trial section was built employing this material as a pavement base course in a heavy traffic highway in Brazil, and its structural behavior was monitored for 12 months using a Falling Weight Deflectometer (FWD) to assess its performance over time. Furthermore, a laboratory‐testing program was performed to evaluate the recycled mixture stiffness and strength through resilient modulus and indirect tensile strength tests. These tests were used to investigate the influence of the storage interval (7, 14, and 28 days) considering the time between mixing and compaction of the mixture. The effect of the curing time after compaction (1, 3, 7, 26, and 56 days) was also assessed. It was verified in laboratory and in the trial section that the stiffness increases with curing time. Furthermore, the backcalculated elastic resilient moduli indicated values in the same order of magnitude to those obtained in the laboratory tests. In addition to the laboratory test findings, it was also observed that the longer the period of storage, the higher the values of stiffness and tensile strength for short periods of curing. This behavior was not verified when longer curing periods were used. In general, the use of cold recycled asphalt mixtures as base course of new pavements proved to be a promising alternative to reuse RAP.

Effects of road traffic noise on the prevalence of cardiovascular diseases: The case of Thessaloniki, Greece

Road traffic noise is a growing challenge for human health in the last decades. World Health Organization (WHO) summarized the scientific evidence on side effects of noise on public health and wellbeing since 1999 in its publication “Guidelines for community noise”. The WHO’s documentation was completed in 2009 with the Night Noise Guidelines for Europe and in 2011 with the Burden of disease from environmental noise highlighting the negative effects of environmental noise on health.In this paper, we studied and presented the overall noise levels and the exposure of the population in the city of Thessaloniki, Greece.The estimation of the exposure to road traffic noise was based on the census data for a 15-year time period (e.g. 2000–2015).The quantification of the environmental burden of cardiovascular diseases, due to urban traffic noise, is calculated in terms of DALYs. The calculation is based on the morbidity and mortality data from the hypertensive, ischemic heart, and cerebrovascular diseases of the total population.Our analysis proved that the road traffic noise in Thessaloniki causes almost 2000 DALYs lost in the total population each year.Also, the exposure to road traffic noise was estimated by three measuring points, two of them located in the urban Thessaloniki (a high traffic highway and a residential area) and the third one situated in one urban background area in the urban outskirts of Thessaloniki.The noise levels were measured for a 24-h period during a 3 year time period for every measuring point. The imposed WHO noise levels were exceeded in both high traffic highway and residential areas for almost the whole time of the measurement period.