public static function computeLength($path) {
        if (count($path) < 2) {
            return 0;
        }
        $length = 0;
        $prev = $path[0];
        $prevLat = deg2rad($prev['lat']);
        $prevLng = deg2rad($prev['lng']);
        foreach($path as $point) {
            $lat = deg2rad($point['lat']);
            $lng = deg2rad($point['lng']);
            $length += self::distanceRadians($prevLat, $prevLng, $lat, $lng);
            $prevLat = $lat;
            $prevLng = $lng;
        }
        return $length * MathUtil::EARTH_RADIUS;
    }