Heavy Traffic Roads Research Articles

Traffic-related pollutants in roadside environment of Yangon, Myanmar

Roadside environment is a key location responsible for increased exposure of traffic-related air pollutants to people who reside, work and commute on or near the roadside. Although increase in traffic volume and duration of traffic congestion has been significantly recognized in Yangon, research conducted on traffic-related air pollutants is very limited. In this study, we mainly focused on nitrogen dioxide and aromatic hydrocarbons of VOCs; benzene, toluene, ethylbenzene and xylenes collectively known as BTEX. Dffusive air samplers; DSD-CX for BTEX and DSD-TEA for NO2 were placed at seven sampling sites, S1-S4 located on heavy congested traffic roads of commercial areas and S5-S7 on fast moving traffic roads of residential ones. The BTEX concentrations were measured by gas chromatography/mass spectrometry and NO2 by ion chromatography. According to the findings, we concluded that roadside NO2 concentrations reflect the severity of traffic congestion currently encountered in the city. Sources other than vehicle emission could also have contribution to roadside traffic-related pollutants. Appropriate traffic managements and vehicle emission controls are urgently needed for reducing traffic-related air pollution.

Study of a Highly Effective and Affordable Highway Interchange - ITL Interchange

In this paper we present a new solution for the highway interchange, which represents the best compromise between the traffic capacity, the land area used and construction cost. The difference between the known and the new design solution is in the implementation of the opposite directional ramps which are widely separated in the area of the interchange. In the middle, between the directional ramps, some space is created for the left directional ramps. Interchange should be used for four-way highway interchanges or other heavy traffic roads junction in order to increase the capacity and traffic safety at the crossing point. It has no conflict points. ITL Interchange left directional ramps is much shorter than all other known solutions for interchanges. The interchange is built in two levels. These two facts significantly lower the cost of construction. The study compares different types of interchanges. We made a geometric comparison and performance measures. In geometric comparison, the greatest advantages of the ITL interchange are the shortest overall roadway length and the shortest overpasses length. Therefore, such an interchange is advantageous in terms of construction and maintenance costs. When measuring performance, ITL Interchange achieves the best results regardless of the number of vehicles.

Effects of wind speed and atmospheric stability on the air pollution reduction rate induced by noise barriers

People around the world increasingly live in urban areas where traffic-related emissions can reach high levels, especially near heavy-traffic roads. It is therefore necessary to find short-term measures to limit the exposure of this population and noise barriers have shown great potential for achieving this. Nevertheless, further work is needed to better understand how they can act on pollution reduction. To do this, a Reynolds-Averaged Navier-Stokes model that takes into account thermal effects is used to study the effects of wind speed and atmospheric stability on the concentration reduction rates (CRR) induced by noise barriers. This study shows that the CRR behind the barriers may depend on both wind and thermal conditions. Although only the wind direction, and not the wind speed, has an impact on CRR in a neutral atmosphere, this parameter can be changed by both wind speed and thermal variations in non-neutral atmospheres. Stable cases lead to a higher CRR compared to unstable cases, while the neutral case gives intermediate results. Finally, it is shown that the variation of CRR is negligible for Richardson numbers ranging from −0.50 to 0.17.

A Study on Hybrid Sensor Technology in Winter Road Assessment

Road conditions during the winter months in Nordic countries can be highly unstable. Slippery roads combined with heavy haul traffic and ordinary road users can create dangerous, even lethal, situations if road maintenance is unsuccessful. Accidents and critical road conditions may lead to blocked roads, putting strain on a limited number of main roads in many regions, and may in the worst case isolate areas entirely. Using sensors in winter road assessment has been a popular topic for over 20 years. However, with today’s developments connected to smaller and cheaper sensors, new opportunities are presenting themselves. In this study, we performed preliminary experiments on a variety of sensors, both commercial and experimental, to evaluate their benefits in possible hybrid sensor technology, which can give a more complete characterization of the road surface than what is possible from just one sensor. From the collected data and visual analysis of the results, the idea of a hybrid sensor seems promising when considering the differences in the tested sensors and how they may complement each other.

Fatigue performance assessment of recycled tire rubber modified asphalt mixtures using viscoelastic continuum damage analysis and AASHTOWare pavement ME design

Improving fatigue cracking resistance of asphalt mixtures is an important issue that concerns roadway agencies, public and industry. There are various, well-established methods for improving the material characteristics, such as polymer modification methods. Recycling/reusing scrap tire rubber in asphalt pavements has also been an interest of engineers. As such, many different methods of scrap tire rubber (herein called crumb rubber) modification alternatives are being developed. This study focused on a comparative evaluation of the fatigue cracking resistance of various base and recycled tire rubber modified asphalt mixtures, including the relatively new and innovative devulcanized rubber (DVR), crumb rubber terminally blend (CRTB), crumb rubber wet process (CRWET), original/base PG58-28 and softer PG58-34 binders, by using Push-Pull Viscoelastic Continuum Damage (PP-VECD) analysis and AASHTOWare Pavement Mechanistic Empirical Design (Pavement ME) software. The results of the study revealed that rubberized asphalt mixtures provided better fatigue lives than the base and softer binders did. Especially, DVR mixtures outperformed at high strain levels, implying they can be used for heavy traffic roads to enhance the fatigue life of asphalt pavements. Both PP-VECD and Pavement ME produced results that showed similar trends.

KAJIAN PARAMETER MARSHALL DENGAN MENGGUNAKAN LIMBAH SERBUK KERANG HIJAU SEBAGAI FILLER CAMPURAN LAPIS ASPAL BETON

This inquiry aims to investigate whether the use of green mussels shell powder as an alternate filler in Laston mix can meet the Marshall parameter or not. Method used in this inquiry is experimental method that examines Marshall parameter at various percentages of green mussels shell powder use in which their level are 0%, 6,5%, 7,5%, and 8,5% as an alternate of half of filler. The experiment of green mussels shell powder is generate a maximum level of filler at 7,5% percentage with stability value in 987,478 kgs, flow value in 3,70 mm, Marshall Quotient value in 266,738 kgs/mm, Void in Mineral Aggregates value in 17,597%, Void Filled with Bitumen value in 71,958% and Void In the Mix value in 4,709%. By this result, it can be concluded that green mussels shell powder can be used as an alternate filler in AC-WC asphalt mix for heavy traffic road with 7,5% percentage of filler level.

Theoretical analysis of stone pavers in pedestrian areas

This paper compared two approaches used to analyze a modular pedestrian pavement made of hexagonal basalt pavers. In presence of occasional heavy traffic roads, the pavement should be verified using methods currently used for road pavements. Different loading conditions were examined varying the geometry of the blocks, and the magnitude of the vertical load. In all cases, the results obtained from the analytical theory of Westergaard were higher than those obtained from a finite element model (FEM). Therefore, a parametric study was performed in order to use the analytical method as an alternative to the costly FEM approach. The results of comparison gave a correction factor, valid for hexagonal pavers: it permits to analytically estimate with good approximation the stresses induced by heavy loads applied to natural stone blocks.

Interactions between dietary habits and home environmental exposures on respiratory symptoms in Romanian school children: an analysis of data from the SINPHONIE project.

In this study, we investigated the interactions between household pollutants and dietary habits on children's respiratory health. Our cross-sectional study collected self-reported information including health symptoms (allergy-like, asthma-like, and flu-like symptoms), home characteristics, dietary habits, and demographic information from questionnaires administered to parents of 280 school children in Romania. Unconditional logistic regression and stratified analyses were used to assess the interactions between dietary factors and environmental exposures on health symptoms among children, controlling for sociodemographic characteristics and co-exposures. We found that frequency of fruit consumption had significant interaction with residing near heavy traffic on allergy-like symptoms among children (p = 0.036). However, no association was observed by frequency of fruit consumption. Although no significant interaction was observed, we found that students with infrequent fruit consumption and residing near heavy traffic roads had elevated odds of asthma-like (POR 6.37; 95% CI 1.22, 33.29) and flu-like symptoms (POR 3.75; 95% CI 1.12, 11.86) than those who frequently consumed fruits. Likewise, low vegetable consumption was associated with increased asthma-like symptoms (POR 2.93; 95% CI 1.04, 8.24). Increased odds of asthma-like symptoms were observed among school children that resided near heavy traffic roads and frequently consumed milk (POR 2.80; 95% CI 1.24, 6.31) and yoghurt (POR 2.86; 95% CI 1.05, 7.75) compared to those that infrequently consumed dairy. Our findings suggest thatfrequent fruit and vegetable consumption may mitigate the negative effects of exposure to heavy traffic near dwelling on respiratory symptoms in Romanian children.

Self-reported traffic-related air pollution and respiratory symptoms among adults in an area with modest levels of traffic.

Health effects of traffic-related air pollution (TRAP) concentrations in densely populated areas are previously described. However, there is still a lack of knowledge of the health effects of moderate TRAP levels. The aim of the current study, a population-based survey including 16 099 adults (response rate 33%), was to assess the relationship between TRAP estimates and respiratory symptoms in an area with modest levels of traffic; Telemark County, Norway. Respondents reported respiratory symptoms the past 12 months and two TRAP exposure estimates: amount of traffic outside their bedroom window and time spent by foot daily along a moderate to heavy traffic road. Females reported on average more symptoms than males. Significant relationships between traffic outside their bedroom window and number of symptoms were only found among females, with the strongest associations among female occasional smokers (incidence rate ratio [IRR], 1.75, 95% confidence interval (CI) [1.16–2.62] for moderate or heavy traffic compared to no traffic). Significant relationship between time spent daily by foot along a moderate to heavy traffic road and number of symptoms was found among male daily smokers (IRR 1.09, 95% CI [1.04–1.15] per hour increase). Associations between traffic outside bedroom window and each respiratory symptom were found. Significant associations were primarily detected among females, both among smokers and non-smokers. Significant associations between time spent by foot daily along a moderate to heavy traffic road (per hour) and nocturnal dyspnoea (odds ratio (OR) 1.20, 95% CI [1.05–1.38]), nocturnal chest tightness (OR 1.13 [1.00–1.28]) and wheezing (OR 1.14 [1.02–1.29]) were found among daily smokers, primarily men. Overall, we found significant associations between self-reported TRAP exposures and respiratory symptoms. Differences between genders and smoking status were identified. The findings indicate an association between TRAP and respiratory symptoms even in populations exposed to modest levels of TRAP.

Snow-dirt sludge as an indicator of environmental and sedimentation processes in the urban environment

The formation of snow-dirt sludge (SDS) via the mixing of snow and surface-deposited sediment by vehicles and pedestrians is one of the least studied sedimentation processes in urban areas. The aim of this study was to analyse the material, mineral, particle size, and chemical compositions of the SDS solid phase. The study was conducted using Ekaterinburg, Russia, as an example city with an intense anthropogenic impact and a long cold snowy period. The average content of the SDS solid phase was approximately 35 g L−1 of meltwater on heavy traffic roads, of which the dust fraction (<0.1 mm) accounted for 23 g L−1. On driveways and lawns, the contents of the SDS solid phase were 12 and 6.6 g L−1, respectively. The mineral composition of the SDS solid phase was generally similar to the geology of the surrounding area, which is composed of a mosaicked combination of felsic and mafic complexes. The presence of building material fragments and other anthropogenic particles confirms the significant anthropogenic impact. The chemical composition contained major and minor elements specific to the minerals and materials that constitute the SDS solid phase. There was significant variability in the concentrations of Pb, Cu, and Zn in the granulometric fractions, indicating pollution. Intensive melting of SDS with a high particulate matter (PM) content is an important factor influencing the environmental quality of the urban environment.

Real-scale study of a heavy traffic road built with in situ recycled demolition waste

This real-scale study carries out a research of the behaviour of building demolition wastes in a road with high intensity traffic. A mobile recycling plant treated in situ the demolition wastes from 105 single-family homes. Recycled aggregates were made from two different sources: one aggregate came from concrete taken out of slabs and foundations (recycled concrete aggregate) and the second aggregate came from the remaining reinforced concrete structures, walls and roofs (recycled mixed aggregate). Both recycled materials and a crushed stone formed the granular base and subbase of the experimental paved section. A leaching test analysed the potential pollutant emissions of the recycled aggregates. Different tests were performed during construction of the experimental section, such as densities, loading plates and falling weight deflectometry. This research evaluated deflections and surface roughness for a period of seven years to study the behaviour of these recycled materials long term. The recycled aggregates used did not satisfy all the stipulations of the Spanish standards for granular material as road subbases/bases, such as size distribution, Los Angeles test limit, soluble salt and organic matter content in subbases. Despite this lack of compliance, the results of on-site tests over time compared the mixed recycled aggregate as subbase and the recycled concrete aggregate as the base with natural aggregates; the recycled aggregates presented a better structural behaviour and less surface deterioration than natural aggregates under a mean daily heavy vehicle flow of 371 vehicles per lane and an average daily traffic of 4469 vehicles per lane on average. The article includes the calculation of moduli through forward and back calculations for the recycled aggregates, which is a key aspect in pavement design The bearing capacity of recycled materials increased with time in the structural layer, which is unlike the trend in bearing capacity of the natural aggregates.

Traffic source impacts on chlorinated polycyclic aromatic hydrocarbons in PM2.5 by short-range transport

Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) are recognized as ubiquitous hazardous pollutants in the environment, whereas their behavior in local areas remains unclear. Additionally, there is limited information on the sources in local areas. Here, we investigated the seasonal trends of ClPAHs associated with fine particles (PM2.5) at two sites near heavy traffic roads to evaluate the local atmospheric behaviors and sources. The annual mean concentrations of total ClPAHs at the north (site A) and south side (site B) across a heavy traffic road were 12.0 and 19.2 pg/m3, respectively. The higher concentration at site B was further emphasized during the winter season; at that time the site was located beneath the wind from the traffic road. In addition, for individual ClPAHs, the behaviors of 8-chlorofluoranthene (8-ClFluor) and 7-chlorobenz[a]anthracene (7-ClBaA) were consistent with the frequency of the north wind, suggesting that 8-ClFluor and 7-ClBaA have the ability to be indicators of vehicle exhaust. Diagnostic ratios using these specific ClPAHs during high-traffic activities provided the specific values to differentiate the impacts.

Study of Umbilical Blood Lead Level and Its Relation with Pregnancy Outcome

مازال التعرض للرصاص يمثل مشكلة صحية تحتاج للاهتمام من الانظمة الصحية المختلفة. تم تصميم الدراسة الحالية لاستكشاف وجود علاقة بين التعرض الأمومي للرصاص ومستويات الرصاص في دم الحبل السري وتحديد العوامل المسببة المحتملة التي قد تؤثر على مستويات الرصاص في الدم السُري العالية وتأثيرها على نتائج الحمل. وقد شملت الدراسة مائة مولود حديث الولادة من أمهات حوامل أصحاء يحملن حملاً مفرداً. تم استخدام نموذج استبيان لجمع المعلومات من الأمهات المشاركات فيما يتعلق بالبيانات الديموجرافية وتاريخ الحمل وتم سحب عينة دم من الحبل السري لكل طفل حديث الولادة لتحديد مستوى الرصاص بها. كشفت الدراسة أن مستويات الرصاص العالية في دم الحبل السري كانت مع الأمهات الحوامل اللاتي يسكن أو يعملن بالقرب من الشوارع أو الطرق المزدحمة وأيضا العيش بالقرب من ورش الطلاء وأماكن حرق النفايات وأيضا شرب الشاي أو القهوة أو الشاي الأخضر. وأيضا الأمهات الحوامل اللاتي كانت نسبة الهيموجلوبين لديهن منخفضة. بينما كانت مستويات الرصاص المنخفضة في دم الحبل السري مع الأمهات الحوامل اللاتي يتناولن مكملات الحديد والكالسيوم. كما كشفت نتائج الدراسة أيضا أن هناك علاقة بين ارتفاع مستوى الرصاص في دم الحبل السري ونتائج الحمل متمثلة في انخفاض ملحوظ في القياسات البشرية (الوزن، الطول، ومحيط الرأس). أن وجود مستويات عالية من الرصاص في دم الحبل السري يعكس أضراراً جانبية على صحة الأم والجنين.

Determination and Contamination Assessment of Heavy Metals in Street Dust from Different Types of Land-Use in Kathmandu District, Nepal

A total of forty seven street dust samples, collected from five different types of land use viz., industrial, urban, heavy traffic road, residential and undisturbed areas (control) of Kathmandu district (Nepal), were subjected to characterize the physico-chemical parameters such as pH, electrical conductance (EC), total alkalinity (T. Alk), total organic carbon (TOC) and particle size distribution. Four heavy metals of Cd, Cu, Pb and Zn were determined in dust samples using flame atomic absorption spectrophotometer (FAAS). It was found that all types of dust samples possessed alkaline nature along with variation in EC, T. Alk and TOC values. Results revealed that the dust of industrial areas contained high concentrations of Zn (143.3 mg/kg) and Cu (106.42 mg/kg), whereas the heavy traffic areas were mainly affected by Cd (0.90 mg/kg) and Pb (70.08 mg/kg). The average metal concentrations of Cd, Cu, Pb and Zn in dust of all the types of land use in Kathmandu were found to be 0.73, 68.86, 51.46 and 104.30 mg/kg and their average metal enrichment factors were 2.28, 5.50, 1.92 and 3.17, respectively. The results were also compared against heavy metals status in street dust from various cities/countries around the world. Pollution indices such as contamination factor (CF), degree of contamination (CD) and geo-accumulation index (Igeo) showed different classes of metal contamination in street dust of Kathmandu indicating traffic emission, automobiles, construction and demolition activities and other anthropogenic activities as the potential sources.

Association of Traffic-Related Air Pollution (TRAP) with DNA Damage and Respiratory Health Symptoms among Primary School Children in Selangor

Exposure to Traffic-Related Air Pollution (TRAP) is a public health concern accountable for several health problems each year in Malaysia. Several studies globally have shown that children in schools near high traffic roads have increased risks for Deoxyribonucleic Acid (DNA) damage due to higher exposure to TRAP. The study aimed to determine the association between TRAP exposure with DNA damage and respiratory symptoms among school children in Selangor state. PM2.5, PM10, Ultrafine Particle (UFP), Carbon Monoxide (CO), Carbon Dioxide (CO2), Nitrogen Dioxide (NO2) and Sulphur Dioxide (SO2) were measured as TRAP. A cross-sectional comparative study was carried out among children in Kajang as exposed group (n=52) and Hulu Langat as comparative group (n=52). A set of standardized and validated questionnaires were used to determine respiratory symptoms and history of exposure. Measurements of indoor and outdoor air pollutants were conducted in schools. Buccal mucosa cells were collected, which then followed by investigation of DNA damage using a comet assay. All pollutants were significantly associated with reported cough and wheezing at p<0.05. Meanwhile, PM2.5, PM10 and UFP were significantly associated with comet tail length at p<0.05. Additionally, comet tail length in the exposed group was significantly higher (35.95±7.93 μm) than those in the comparative group (30.32±8.358 μm), and the difference was significantly different (t=3.450, p=0.001). Children were more likely to have genotoxicity of buccal mucosa if they were exposed to higher levels of ultrafine particles (UFP). This study demonstrated that children in schools near heavy traffic roads have an increased risk for respiratory symptoms and DNA damage due to higher exposure to TRAP. Therefore, this study supports its importance as a risk factor in associations documented between TRAP and respiratory health among children.

Ground tire rubber and bitumen with wax and its application in a real highway

This research shows results over the structure-property relation of Ground Tire Rubber (GTR) modified after a high shear mixing process using wax as rejuvenator agent in a product under the environmental and technical regulations. The GTR was used after a milling process which produced a mean particle size of 1.19 mm. Bitumen 60/70 type was mixed with the rubber waste at 4000 rpm at 190 °C. A set of 15 formulations with rubber waste ranging from 10 to 20 wt% were prepared by following the Box-Behnken experimental design. Gradation tests were conducted over the GTR. Penetration, softening point, elastic recovering and viscosity tests were conducted over all formulations. Scanning electron microscopy with energy dispersed spectroscopy was used to analyze the microstructure and the chemical composition of samples. The effects of the main variables and their combinations over the properties have been analyzed. Using the desirability criterion, three different formulations were found to follow the specifications, and the best composition of them was the sample with GTR 15 wt%, 40min agitation time, and 3 wt% of rejuvenator, with a coefficient of determination of R2 = 0.9924. Results were successfully scaled up in a large manufacturing process by a road construction company and applied in a heavy traffic road at Colombia.

Genotoxic assessment of selected native plants to deferentially exposed urban ecosystems.

The aim of this study is to provide an analysis of the impact of ecogenotoxicity on native flora abortivity in various urban areas. In which, there was an analysis of 5 groupings of locations with a differing environmental load intensity within the city of Bratislava (Slovakia) over a 2-year period. Our results show varying data depending on the proximity of each site relating to a direct source of pollution and the potential impact of localized wind currents on the distribution of pollutants in the urban environment. The highest value of pollen abortivity in the city was observed in a group of locations exposed to heavy traffic pollution loads. Abortivity of native flora near heavy traffic road areas correlated with the imissions data measured in the same area. Wind-exposed uncovered sites also experienced higher values of native flora abortivity. These results confirmed the varying intensity of genotoxic impact in differing localities and also suggest that xenobiotic effects on flora can occur remotely from the original source of pollution.

Health risks from PAHs and potentially toxic elements in street dust of a coal mining area in India

Polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) (Ba, Zn, Pb, Cu, Cr, Ni, As, Co) were determined in the road dusts of a coal mining area (Dhanbad, India) to assess their content and potential human health risks. Dust samples were collected from sign boards of the heavy traffic road connecting Dhanbad and Sindri. The total PAHs (∑PAHs, all values in mg/kg) content in the road dust samples varied from 3.98 to 13.1, with carcinogenic PAHs content of 14.8-34.4% of the ∑PAHs. Phenanthrene (2.72), fluorene (0.715) and pyrene (0.575) are the major PAHs. Principal component analysis revealed that these PAHs are probably originated from pyrogenic (coal combustion and traffic emission) and petrogenic (coal dust, tyre and road particles) sources. Among the PTEs, the mean content was higher for Ba (293mg/kg) followed by Zn (224), Pb (128), Cu (52.6), Cr (45.2), Ni (22.0), As (17.5) and Co (8.11). The overall pollution load index varied from 0.43 to 1.0. Source analysis showed that PTEs in the road dust of the study site were derived from traffic emission (Zn, Fe, Mn, Co and Pb), coal dust (Cr, As and Ni) and soil (K, Mg, Ba, Sr and Ca). In general, the PTEs are lower, but the PAHs contents were elevated in the road dust samples. Although the exposure risks from PTEs are low, the risk to children (expressed as hazardous quotient) for As and Pb is near to the permissible limit of 1.0. Cancer risk from PAHs for adult (4.8 × 10-6) and child (5.3 × 10-6) has exceeded the acceptable limit of 10-6.

Analytical and Numerical Approaches for Design of Stone Pavers in Urban Shared Areas

Existing statistical data show that the use of pedestrian block pavements is increasing. This paper compares two approaches used to analyse a block pavement in an urban shared area. In presence of occasional heavy traffic roads, the pavement should be verified using methods currently used for road pavements. The analytical theory of Westergaard and the commercial finite element (FE) software Abaqus® were used to calculate the response of the pavement when subjected to different loading, and geometrical configurations. In all the examined cases, the results obtained from the analytical theory of Westergaard were higher than those obtained from the adopted static FEMs. Therefore, a parametric study was performed in order to use the analytical method as an alternative to the costly FEM approach introducing a Dynamic Amplification Factor (DAF). The results of comparison gave interesting results, valid for hexagonal pavers: it is possible to estimate analytically with good approximation the stresses induced by heavy loads applied to natural stone blocks. This is an interesting result since the analytical theory provides an inexpensive procedure for the analysis of modular pavements.

A Low-Cost Open Hardware System for Collecting Traffic Data Using Wi-Fi Signal Strength.

Road traffic and its impacts affect various aspects of wellbeing with safety, congestion and pollution being of significant concern in cities. Although there have been a large number of works done in the field of traffic data collection, there are several barriers which restrict the collection of traffic data at higher resolution in the cities. Installation and maintenance costs can act as a disincentive to use existing methods (e.g., loop detectors, video analysis) at a large scale and hence limit their deployment to only a few roads of the city. This paper presents an approach for vehicle counting using a low cost, simple and easily installable system. In the proposed system, vehicles (i.e., bicycles, cars, trucks) are counted by means of variations in the WiFi signals. Experiments with the developed hardware in two different scenarios—low traffic (i.e., 400 objects) and heavy traffic roads (i.e., 1000 objects)—demonstrate its ability to detect cars and trucks. The system can be used to provide estimates of vehicle numbers for streets not covered by official traffic monitoring techniques in future smart cities.