来自google map json url的php echo值

我正在尝试从google map json url回显一个值。我可以var_dump()键和值,但不能单独提取特定值。PHP代码:

<?php
    $from = 'Piccadilly+Circus+London+UK';
    $to = 'Brighton+Railway+Station+Brighton+UK';
    $json ='https://maps.googleapis.com/maps/api/distancematrix/json?origins='.$from.'&destinations='.$to.'&mode=driving&key=APIKEY';
    $ch = curl_init($json);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    $data = curl_exec($ch);
    curl_close($ch);

    // Print Result
    echo '<pre>' . var_dump($data) . '</pre>';

?>

var_dump()结果如下;

       string(542) "{
       "destination_addresses" : [ "Brighton, Queens Rd, Brighton BN1 3XP, UK" ],
       "origin_addresses" : [ "Piccadilly Circus, London W1B, UK" ],
       "rows" : [
          {
             "elements" : [
                {
                   "distance" : {
                      "text" : "86.7 km",
                      "value" : 86665
                   },
                   "duration" : {
                      "text" : "1 hour 59 mins",
                      "value" : 7114
                   },
                   "status" : "OK"
                }
             ]
          }
       ],
       "status" : "OK"
    }
    "

我需要分配 距离->文本 一个php变量。有人能帮忙吗?