The KeNHA boss is serving his second three-year term, which expires on August 27.
Mr Opudo says Mr Mundinia should have proceeded on terminal leave to pave the way for the hiring of his successor.
An activist has gone to court seeking to compel Kenya National Highways Authority (KeNHA) director-general Peter Mundinia to quit office, pending his retirement next month.
In a case certified as urgent, Charles Opudo says Mr Mundinia's term expires next month but he is still in office contrary to the Kenya Roads Act and KeNHA human resource manual and the constitution.
The KeNHA boss is serving his second three-year term, which expires on August 27.
Mr Opudo says Mr Mundinia should have proceeded on terminal leave to pave the way for the hiring of his successor.
The parties appeared before Justice Nduma Nderi last week. Mr Opudo, through his lawyer Majimbo Mamboleo, requested to be allowed to amend part of the petition.
He argues that the timely recruitment of the new CEO will facilitate a smooth and seamless transition to the new administration.
Mr Opudo has sued KeNHA chairman Wangai Ndirangu, Transport Cabinet secretary James Macharia and the Public Service Commission.
Mr Mundinia was reappointed on August 28, 2018. The Act, according to Mr Mamboleo, provides that one must proceed for terminal leave, pending retirement.
He told the court that it would be irregular and contrary to the Constitution for Mr Mundinia to continue discharging his duties.
The lawyer asked the court to compel the agency to commence the process of recruiting a new director-general as required by the law.
"The respondents have not commenced the process for replacing him nor appointed an acting or caretaker director-general and have failed to announce the vacancy to attract interest and qualified candidates for Institute of Engineers," he said in an affidavit.
The case comes in the wake of a proposed Kenya Roads (Amendment) Bill 2021 that seeks to extend terms of director-generals of the authorities from the current three to five years.
The Bill introduced was introduced by Pokot South MP David Pkosing and is being considered by the departmental committee on Transport, Public Works and Housing, which he chairs before being submitted to the House.
The proposal also seeks to add other qualifications to be met by a person nominated as director-general, among them, the new qualifications of a bachelor's degree in civil engineering and a master's degree.
