def clean_col_names(df):
    """
    cleans up the column names in the mta dataframe

    :param df: mta dataframe
    :return: mta dataframe with cleaned columns
    """
    df = df.copy()
    before = 'EXITS                                                               '
    df.rename(columns={before: 'EXITS', "C/A": "CA"}, inplace=True)
    return df