(a) Any two or more of the persons involved in or affected by an accident may enter into a written agreement for the payment of an agreed amount with respect to all claims of any of such persons because of bodily injury to or death or property damage arising from such accident, which agreement may provide for payment in installments, and may file a signed copy thereof with the department. (b) The department, to the extent provided by any such written agreement filed with it, shall not require the deposit of security and shall terminate any prior order of suspension or, if security has previously been deposited, the department shall immediately return such security to the depositor or his personal representative. (Ga. L. 1951, p. 565, § 6; Code 1933, § 68C-305, enacted by Ga. L. 1977, p. 1014, § 1.) 40-9-36. Amount of security; designation of persons for whom deposit made; reduction or increase in amount. (a) The security under this chapter shall be in such amount as the department may require, but in no case in excess of the limits specified in subsection (a) of Code Section 40-9-37. Every depositor of security shall designate in writing every person on whose behalf the deposit is made and may at any time change such designation, in writing, to include an additional person or persons; provided, however, that a single deposit of security shall be applicable only on behalf of persons required to furnish security because of the same accident. (b) The department may, upon written notice to all parties involved, reduce or increase the amount of security ordered in any case within six months after the date of the accident if in its judgment the amount ordered is excessive or inadequate. In case the security originally ordered has been deposited, the excess deposit over the reduced amount ordered shall be returned to the depositor or his personal representative. (Ga. L. 1951, p. 565, § 9; Ga. L. 1956, p. 543, § 17; Ga. L. 1963, p. 593, § 6; Code 1933, § 68C-307, enacted by Ga. L. 1977, p. 1014, § 1.)