Evaluation of the Selected Sustainable Indicators for Urban Roads Network: Al-Kufa City as a Case Study

One of the major concerns of the modern world is sustainable development. Sustainable transportation development is crucial in light of the increasing congestion and pollution in urban areas. Al-Kufa City is one of the most significant cities in Iraq. This study focuses on specific criteria such as public transportation, pedestrian facilities, pavement markings, noise level, and population density on the number of existing roads. The collected data showed that the average percentage of public transportation at selected locations is 4% for buses and 24.6% for minibuses with unplanned routes. Furthermore, pavement markings cover only about 0.48% of the whole network. Regarding the noise level, it was high and exceeded the standard limitations, reaches to 93.48 dBA. At the same time, the indicator of pedestrian facilities showed a significant lack of footbridges. Finally, the density of roads per population is 60.32km/100000 which is less than the expected value. Therefore, actions and improvements are necessary for the short and long term to develop a sustainable city living environment.


Introduction
Transportation is a central dimension of the national and global production systems reshaping the world, making it a topic of universal interest and importance [1].There has been a notable increase in concern about the sustainability of urban environments in both scientific and popular literature in recent years [2].
Urban transport has several negative impacts that can hinder the achievement of sustainability targets.According to the Transport and Environment Reporting Mechanism (TERM) (2000), these can be prevented by identifying key indicators that can be tracked and compared with strong policy objectives [3].The users choose their mode of transportation based on their socio-economic standing and the reason for their trip, making the urban transportation network a key institution responsible for developing urban centers [1].For a city to have a sustainable urban structure, it must be a manageable size for various human activities, including bicycling, walking, and using public transportation.As a result, land can be used more effectively, fewer cars are needed for transportation, reduced pollution, people can move around easily, and people can rest easy in comfortable living conditions [4].Public transit is a fundamental approach that significantly contributes to sustainable mobility.Congestion, pollution, and accidents caused by individual vehicles could all be mitigated by switching to public 1232 (2023) 012051 IOP Publishing doi:10.1088/1755-1315/1232/1/012051 2 transit [5].Therefore, this study aims to evaluate sustainable indicators such as public transportation, noise level, pavement markings, pedestrian facilities, and density of road per population in the study area.

Public transportation
Urban transport crises are common in many cities due to economic growth and fast urbanization.Unprecedented increases in the quantity and use of private vehicles have caused significant traffic jams, high accident rates, air pollution, and greenhouse gas emissions [6].The existing public transportation system in al-Kufa city is plagued by insufficient accessibility.Constantly increasing traffic and congestion were direct results of our reliance on personal automobiles as a primary mode of transportation.People's insistence on using their automobiles as their primary means of transportation is reflected in the widespread occurrence of traffic jams [7].The directly observable impact of road congestion is the increase in travel times along congested network links [8].Inadequate public transportation infrastructure increases the time it takes to get about and the cost of running vehicles that make getting around the city more complicated [7].Additionally, everyone can use public transit instead of only those who own and are licensed to drive cars.Therefore, cities require and profit from public transportation systems that provide higher population mobility than is possible in rural areas [9].A public transportation system's effectiveness is determined by its price, capacity to meet demand, and transfer times [10].

Noise in urban streets
Displeasure, disruption, and aggravation are all feelings associated with noise annoyance [11].One of the most significant environmental health dangers is noise, an increasing issue for the public and policymakers [12].In modern cities, road traffic is a significant source of unwanted noise [13], [14].As the European Environment Agency reported, vehicular traffic is a significant contributor to noise pollution.When talking about environmental noise, referring to all of the distractions and potentially scary sounds that come from human activities like driving, flying, and working in factories outside [15].Recent World Health Organization (WHO) publications emphasize that environmental noise can be viewed as a contaminant that significantly impacts public health [16].Being subjected to noise levels from traffic that are dangerous to one's health (more than 55 dB) [17].The European Union recommends a threshold of 55 dB for environmental noise [18].WHO recently concluded that noise from traffic raises the risk of ischemic heart disease and perhaps other cardiometabolic disorders like stroke, obesity, and diabetes [18].Most people are impacted in urban areas because that is where they spend the most time and are thus most susceptible to hearing damage from loud noises [15].In addition, the higher level of the road class leads to a higher noise level, namely, expressway > arterial road > sub-arterial road and local road [14].Heavy traffic volume, greater speeds, and a rise in the number of trucks all contribute to an increase in traffic noise levels.The engine, the exhaust system, and the tires all contribute to what we hear as "vehicle noise."[19].
More than 94% of EU citizens living in urban areas are subjected to noise levels greater than 55 dBA per Lday from vehicles, 6% from trains, and 2.2% from airports [20].Noise levels vary depending on the type of vehicle.Due to their high axle loads, trucks are among the loudest vehicles.A truck's axle load can be decreased from about 2000 kg to 500 kg, which results in a 15 dB(A) reduction in noise.Vehicle speed is a significant contributor to the noise from traffic.Because of the friction created by the tires on the pavement, a vehicle makes more noise the quicker it moves.When speed rises, friction noise overtakes engine noise.Other considerations include the amount of traffic, the proportion of heavy vehicles in the traffic flow, and the type of vehicle and its speed [19].Distance between the transmitter and receiver, ground absorption, obstruction by noise barriers, obstruction by a restricted angle of vision, and the reflection affect all impact signal reception at a reference distance from the highway [19].According to Central Pollution Control Board (CPCB), Table 1 shows the standard noise levels for different areas [21]: Most urban areas are experiencing an alarming increase in traffic noise, causing concern for those living near major thoroughfares.The adverse effects of noise on society can be mitigated by limiting its level.There are a few possible outcomes that could lead to lower noise levels: motor vehicle regulation, noise barriers, dead-end streets for residential complexes, lowering freeways and arterial roads to ground level, and increasing the distance between roads and buildings were all proposed as possible solutions to the problem of noise pollution [22].

Pavement markings
Road markers are a simple but effective safety measure seen on most paved roadways [23].Lines or markings painted into the road surface, known as pavement markings, provide crucial directions to drivers regarding lane boundaries and traffic flow.If followed, these markings improve drivers' safety [24].Pavement markings, in every case, are to be understood as long lines and not as objective markers or delineators [25].Certain areas of the road, such as the edge of a median or when the pavement is primarily sandy or slick, may make pavement markers challenging to see.The wear and tear from constant foot traffic necessitate routine maintenance because moving vehicles can obscure them from view [26].They stand out among other traffic control devices since motorists do not need to take their eyes off the road to read them [27].

Pedestrian facilities
One of the most common users of city streets, pedestrians are especially at risk in unprotected mid-block sites while dealing with varying traffic volumes [28].Because it contributes to both land use planning (such as urban redevelopment and more compact "smart growth") and transport planning (such as reduced traffic and parking congestion, energy consumption, and pollution emissions), walking is the most environmentally friendly mode of transportation [29].In many cases, pedestrians who cross the street illegally have been at fault for traffic accidents.For the past few years, there has been a growing awareness among residents and experts in the field of urban planning on the issue of pedestrian safety.Crosswalks help prevent traffic accidents by minimizing collisions between pedestrians and drivers [30].According to the world health organization, about 1.3 million people die annually as a result of traffic accidents [31].As many as 28% of all crash casualties were pedestrians.Accidents involving pedestrians make up 83.7% of all traffic fatalities, and males of all ages are more likely to be the reckless cause of collisions than women [32].The majority of studies show that the number of pedestrian accidents rises in correlation with the volume of vehicular traffic [28].Injury risk to children is 13% higher in the most congested areas compared to the least congested ones [33].Similarly, [34] indicated that compared to low-volume roads, arterial roads in China with higher traffic volumes are responsible for more serious pedestrian crashes.Some people, although having the option of using footbridges, elect instead to use level crosswalks or to cross the road aggressively [35].

Density of road per population
The density of roads is a crucial criterion that reflects the region's economic development.It gives an idea of its adequacy or lack thereof within the governorate.It is a quantitative method for evaluating the service provided by the road -measuring the density of roads expressed in the lengths of paved roads about a unit area or concerning a numerical unit of population.By 2050, approximately 66% of the world's population is predicted to reside in cities, marking a dramatic shift in the worldwide population distribution from rural to urban areas [36].Understanding the interconnections between urbanization patterns, infrastructure, and socio-economic indicators is crucial for achieving sustainable urban development [37].Planning a sustainable transportation system requires an examination of the connections between the population and various modes of transportation [38].The simplest definition of density population divided by area is "gross density" [39].Interaction in the city is summarized in the movement of people who are driven by their activities and their economic and social goals [40].

Description of the study area (Al-Kufa city)
Al-Kufa city in Iraq is located to the northeast of Najaf Governorate, about 170 km south of Baghdad as indicated in Figure 1.Al-Kufa is located along the banks of the Euphrates River, with a total area of 550 km 2 and inhabitants of about 194,609 persons in 2020 [41].

Data collection
Data collection is an integral part of any evaluation strategy.Traffic volume was recorded by camera observation.Decibel readings were taken with the help of a handheld noise meter in October and November /2022 in the morning at peak hour periods (6:00 AM-9:00 AM) during good weather.Table 2 shows the locations of sites in the city.

Traffic volume analysis
The chosen network's traffic volume was recorded by camera observation to understand the network's unique traffic patterns better.High-definition cameras were placed at strategic roads and exit to record traffic patterns.In the light of the figures above, it was found that the private automobile is the most preferred mode, and the users use this mode for travel within the city.To mitigate traffic congestion, traffic injuries and improve air quality is crucial to encourage people to switch to public transportation.This could be contributed to reducing the use of automobiles in crowded places like central business districts and limiting parking usage.

Noise analysis
Noise levels were analyzed in three main streets in Al-Kufa city in conjunction with traffic flow level.Decibel readings were taken with the help of a handheld noise meter.Aside from the median, it was also placed on the side of the road in the study area.Moreover, the variations of noise levels with the flow on the selected street of the network were investigated as given in Figures 14 and 15, respectively.The maximum noise level in Al-Kufa-Najaf was about 88.7 dBA at a flow rate of 1920 veh/hr.The increase in flow also increases the noise level.However, when the road reaches capacity, the noise level decreases gradually.In Link III, the maximum noise level was about 93 dBA and the minimum was 83 dBA.It varies with traffic flow along the observation period.In Al-Maamal street, the maximum noise level is 83 dBA, and the minimum is 74 dBA as shown in Figure 15.

Pedestrian facilities analysis and street classes
The field survey in the city indicates that just three footbridges are there as indicated in Table 3.Furthermore, the details of each site and the existence of these bridges in 2010 and 2022 are shown in Table 3.Moreover, no tunnel facilities exist in the city for pedestrian facilities.
Table 3.The coordination of footbridge in the city.
In line with the HCM classification for urban streets, the class for each street has been determined based on FFS.Referring to Table 4 with the field survey in the city, it was found that there is a need to install footbridges throughout the city.These footbridges could be installed for all multilane roads, Class I and Class II urban streets due to the high interaction along these roads.Al-Kufa city has only three footbridges.

Analysis of roads density
To determine road density, two factors are used (population and area).In this way, density provides a proxy for the effectiveness of the road network in the research region, providing a holistic understanding of the challenges facing the road system and suggesting long-term solutions.Assess the effectiveness of these roads in the research region.It is helpful to indicate the area's economic development and a rough estimate of the number of roads.The density of roads to the area= lengths of the roads (km)*1000/ (the area served by roads (km2)) Al-Kufa City's roadway density = 117.3965*100/49.4422=237.4419km length for each 1000km 2 .Because of this, the city's density exceeds the required level (105km/1000 km 2 ) [42].Estimating the proportion of people on roadways is as simple as: The density of roads to population=lengths of roads (km)*100,000/population =117.3965*100,000/194,609Therefore, the density for 2020 is 60.32 km/100,000 people.This result is less than the standard specification which is (496km/100000people) [42].

Discussion of the results
The findings of this study could be summarized as follows: 1.There is a significant lack of public transport in the main street of Al-Kufa city, the maximum percentage of buses in Al-Kufa-Najaf street is 6%, and mini buses 21% during the analysis of data collection represented by figures mentions previously in the peak hour period.The percentage of private cars is 73% of the traffic composition.2. On the other hand, the maximum average noise level reaches (88.7, 83.02, 93.48) dBA in Links I, II, and III, respectively.These are above the WHO and CPCB standard limits of 55 dBA and 65 dBA.3. The investigation of pavement markings in the whole network of Al-Kufa city shows that 0.48 % of roads have pavement markings.4.There is a significant lack of pedestrian facilities, especially on the footbridge in Al-Kufa city.
The total number is equal to (three) for the whole city. 5.As a percentage of land area, the density road of the city is 237.4419kilometers per square kilometer, which is significantly greater than the standard value.However, as a percentage of the population, it is significantly lower at 60.32 kilometers per hundred thousand.

Conclusions and recommendations
Based on collected data and analysis results, the following are the main significant points:  Under existing traffic conditions, the road network has a relatively low degree of sustainable activity such as a lack of public transport in Al-Kufa city and an increase in the percentage of private cars that lead to high congestion, pollution, and noise that make the traffic in the city unsustainable. Al-Kufa city suffers from noise pollution.The results show that the main streets in the city have high noise such as Al-Kufa-Najaf street and near Muslim bin Aqeel tunnel, where the traffic flow is the highest among other roads in the network. The city needs a pedestrian facility where the footbridge is only three in the whole city.The study recommends installing a footbridge on main roads due to the high risk to pedestrian safety. The results obtained from field testing show that the roads are without pavement markings, therefore recommended to create pavement markings because road safety also depends on highquality road marking.

Figure 1 .
Figure 1.The location of Al-Kufa city and the study area.

Figure 2 .
Figure 2. The details of the sites in the study area.
Figures 3 to 12 illustrate the collected traffic data at study area in mid-block urban road segments.The traffic stream is identified as private passenger cars, taxi passenger cars, buses, and minibuses.Figures 3 to 13 show traffic composition for some selected street in Al-Kufa city.

Figure 5 .
Figure 5.The volume in Link II (Al-Mammal Street toward Al-Matar).

Figure 6 .
Figure 6.The volume in Link II (Al-Mammal Street toward Al-Kufa).

Figure 7 .Figure 8 .
Figure 7.The volume in Link III (Tunnel of Muslim bin Aqeel to Al-Kufa dir.)

Figure 9 .
Figure 9.The volume in Link IV (Tunnel of Al-Mukhtar toward Al-Zahra interchange).

Figure 10 .
Figure 10.The volume in Link IV (Tunnel of Al-Mukhtar toward Al-Imam Ali bridge).

Figure 14 .
Figure 14.Noise levels for two links.

Table 2 .
Details of the data collection sites.

Table 4 .
Classes for main streets in Al-Kufa city.