As of December 31,

2022

2021

(in thousands)

Accrued employee costs

$

28,298

$

30,935

Fuel and other taxes

30,491

31,381

Accrued insurance liabilities

9,881

10,986

Accrued expenses

42,955

35,672

Environmental liabilities

3,425

3,459

Deferred vendor income

12,101

11,654

Accrued income taxes payable

4,056

—

Due to related parties

—

258

Liabilities resulting from Additional and Contingent Consideration

5,674

8,813

Ares Put Option

8,575

—

Other accrued liabilities

8,641

4,330

Total other current liabilities

$

154,097

$

137,488