The act of assisting both individual and group efforts to achieve a common goal is known as leadership [16]. A manager may influence their team members to work voluntarily on what has to be done and what should be done by using leadership [17]. Certain small groups execute jobs that have a significant level of risk; in these situations, team leadership is essential for the capacity to manage the risk [18]. Leadership style has an impact on the composition, efficiency, and productivity of teams [19].

Choi et al. [20] noted that some qualities or behaviours have been used to gauge or evaluate leadership. This was emphasized by Hambley et al. [21]. Other qualities of leaders are tolerance, charisma, inspiration, readiness to accept criticism, team building, and accountability are some of the qualities leaders frequently exhibit [22].

A shared activity may be accomplished by one person with the help and support of others thanks to the leadership, which is a “process of social influence” [21]. In the end, leadership is about finding a way for individuals to contribute their knowledge and abilities to make something possible and go in the right direction [9], [23]. Some leadership theories have been established over time to explain what makes a great leader. Among the models are:

One phrase best sums up this theory: “born to lead” [24]. Exceptional leaders are simply endowed from birth with inner qualities such as charisma, self-assurance, intellect, and social skills that enable them to function as natural leaders [18]. According to this notion, great leaders aren't created; they're born. They naturally possess leadership abilities [25].

According to trait theory, successful leadership is characterized by certain personality traits and behavioural patterns [26]. This assumption explained why some individuals make effective leaders and others do not. Impulse, tenacity, energy, high cognitive abilities and the ability to make wise judgments, adaptability, originality, charm, and confidence are some of the key traits outlined in this approach.

The study of particular leadership behaviours is a key component of behavioural theories of leadership. The primary distinction between these two beliefs is that qualities cannot be taught to a person. While qualities can evolve through time, they are typically not taught to people; instead, they must be learned independently and allowed to grow. Contrarily, behaviors may be taught [27].

Successful teamwork results from some essential traits. Individual activities must first be integrated appropriately by the team. Second, teams must perform in more complex and dynamic contexts [28]. Thirdly, successful team performance is represented by team leadership [23]. Usually, teams include a few key members who are in charge of establishing the team's objectives as well as building and organizing the team to carry out these tasks. Effective teams, according to Zaccaro et al. [18], integrate the four basic processes of cognition, motivation, emotion, and coordination; according to Zaccaro et al. [18], leadership effects on team performance are partly caused by their impacts on these four processes. An essential duty of team leaders is to increase the group's effectiveness.

Team members are more likely to opt to engage in the work if they feel their group is capable of reaching its objectives, or being successful. Leaders who encourage their followers to put in a lot of effort and perform well also increase team efficiency. This relates to how inspiring and transformative leaders empower their followers [29]. Such leaders integrate each member's objectives with the team's or organization's mission through their actions [30]. Team members are more devoted to their success because they identify with the mission and objectives of the group as a whole [31]. As a result, the main goal of transformational leadership is to match each member's motivation with the team's overall goal [31].

The leadership performance evaluation that was carried out by Curry [16] found that the roles of subordinates were greater. This style is referred to as transformational leadership style. In the study of Singer [32] among New Zealand workers, it was identified that subordinates prefer to work with transformative than transactional leaders. This is also similar to the study of Kasapolu [26] among the U.S. Air Force Academy. The following are related with the performance of subordinates by transformational team leaders, considering the performance of subordinates in the literature review. The essential factors are:

I. Team members' effectiveness, II. Extra effort, and III. Satisfaction.

According to Choi et al. [20], an autocratic leader is acutely cognizance of his role and has slight or no trust in the subordinates. He perceives that compensation is merely a reward for labour and that the only thing that can catalyses people is the reward. Long et al. [30] identified six leadership styles, including:

I. Authoritative style task-oriented or structured, II. Persuasive style, III. Democratic style or group developer, IV. Intellectual style or the eminent man, V. Effective style or administrator, and VI. Representative style or spokesman.

According to Guimerà et al. [34], if a leader is weak, inept, or has poor ethical and moral standards, the entire company suffers for the sake of that one leader. Conversely, if the leader is strong, capable, competent, and just, the organization runs well. Many of the advantages of team performance are lost because the output of the team does not benefit from the creativity and experience of all team members.

While followers may comply with the leader's request as a consequence of a transactional leadership approach, excitement and dedication to the task are not likely to arise [35]. The leader concentrates on enlisting internal actors to carry out the duties essential for the organizational goals. The transactional leader aims to guarantee that the internal actors understand the road to goal achievement, remove any potential systemic barriers, and inspire the players to reach the planned goals [36].

Laissez-faire leadership, according to Becker et al. [37], is bad, ineffectual, and leaves followers feeling very unsatisfied. Authoritarian leadership is at one extreme and laissez-faire leadership is at the other [38], with this kind of, leaders trying to delegate the duty of making decisions to the group [17].

The leader lacks confidence in his capacity to lead; hence, the group is loosely organized. Under this leadership, anybody who is willing to take the reins can make decisions [36]. There can be a lot of “buck passing,” and decision-making is also quite sluggish [34]. The work might not be completed as a result, and the situation might conditionally grow chaotic [39]. When team members do not receive adequate direction or input from leaders, projects may deviate and deadlines may be missed. Comparatively, teamwork is less successful than traditional methods [40].

Although democratic leadership has been deemed the most successful, there are some possible drawbacks [41]. Unfinished initiatives and poor communication are known for democratic leadership. The attributes can occur in situations whereby time is of the essence, and responsibilities are unclear [42].

Factors that can impact the quality of a project or engineering activity in Sammya Nigeria Limited on the 10.5km Osogbo-Ikirun Road.

The achievement of acceptable performance standards from construction operations may be referred to as quality in the construction business. When the action satisfies or surpasses the client's need, this performance is achieved. According to Arditi and Gunaydin [43], quality is the achievement of a project's legal, aesthetic, and functional criteria. Jegun and Kothai [44] contend that project success and project quality may both be seen as satisfying client expectations. The control of the quality of the goods or services a construction business offers is one of the crucial parts of the project delivery process.

A program with two distinct components manages the quality of building projects. The Quality Assurance (QA) procedure is one, and the Quality Control (QC) program is the other. The QA element outlines the procedures the contractor will take to achieve it. In contrast, the QC element outlines how the contractor intends to manage the project's quality standards as outlined in the specifications. A product of high quality would perform better under the conditions of its usage, whereas a product of lesser quality will fail in the same circumstances, making QC crucial in the construction sector.

When QC management systems are successfully implemented, product quality may rise, craftsmanship and efficiency can be improved, wastage can be reduced, and profits can rise [45]. Another idea for controlling quality is Total Quality Management (TQM). Every organization in the sector is a part of the TQM initiative, which aims to increase performance. It pervades every part of a business and transforms quality into a strategic goal. To accomplish TQM, all employees must work together to improve performance and boost customer satisfaction continually. For any country's socioeconomic growth, especially a developing one like Nigeria, high-quality road networks are crucial [46].

A lack of quality management principles and tools may lead to frequent changes, errors, and omissions. The single most “unethical” behavior in the business, according to contractors, engineers, and the government, was delivering materials of lesser quality than the contract required, according to a 2011 World Bank report. The five most significant factors that affected construction quality in Nigeria, according to the study of Oyedele et al. [47], there were low levels of skill and labour experience, subpar materials delivered to the site, subpar inspection and testing, subpar site installation procedures, and a lack of QA.

The impact of leadership style and team performance on quality issues in Sammya Nigeria Limited on the 10.5km Osogbo-Ikirun Road. When it comes to quality concerns in building projects, leadership and cooperation are important. The project's leadership style is crucial, and cooperation makes it possible for individuals or groups of individuals to work together on projects. Leadership is crucial in the construction industry, as several studies have shown [48]. According to Thamhain [24], effective leadership is crucial to fostering a positive work environment for the project's participants. There is a tendency for the project manager's job to shift from one that emphasizes management to one that emphasizes leadership, as both are necessary for project leadership success. Although general leadership has been the subject of research for more than a century, Sotiriou and Wittmer [49] point out that project leadership has received relatively less attention from empirical studies.

Project managers must deal with the project's complexity, including its scale, effects on other companies, number of related partners, individuals engaged, time, cost, and uncertainty constraints, as well as any initial project result requirements. According to Crawford [50], a project manager's capacity to lead is a mix of knowledge (ability to work), knowledge (qualification), and key personality attributes (motivations, traits, and concepts) that produce excellent outcomes. The role of the project manager is developing rapidly from management or direction to leading the project with essential leadership skills and competencies.

Bad leadership and subpar teamwork are cited as the cause of low project quality. Also, it is thought that leadership style affects project quality. Based on the six leadership styles that were earlier mentioned, as identified by Long et al. [30], the survey also showed that there are only two prominent leadership philosophies in use today in the big construction companies including Sammya Nigeria Limited: the authoritarian style, also known as a task- or structure-oriented leadership, and the democratic style, often known as a person- or consideration-oriented leadership. The authoritative, task-oriented, or organized characteristics are prevalent in the majority of construction projects [35]. This is a result of the organization's structure and lines of authority. An autocratic leadership style is an authoritarian style. The decision-maker is the leader or project manager, and decisions are based on the objectives the company hopes to accomplish. Some of the leading problems facing the building industry in recent time and in the future are highlighted by Songer et al. [51]. In the operational environment and generally, for enterprises, they highlighted new leadership problems, including sector-specific challenges. According to Toor and Ogunlana [52] research, Thailand's construction projects mostly struggle with poor project management techniques, order management, imposition, inefficient communication, and cultural challenges.

According to Turner and Müller [53], team effectiveness and leadership philosophies are frequently cited as variables that compromise project quality. According to Geoghegan and Dulewicz [54] and Crawford [50], the leadership style used in a building project affects how well it turns out. Crawford [50] said that team performance and leadership style affects the overall project quality of construction projects.