diff --git a/traffic_updater/go/osrm_traffic_updater/get_telenav_traffic.go b/traffic_updater/go/osrm_traffic_updater/get_telenav_traffic.go
new file mode 100644
index 000000000..183c9fa0b
--- /dev/null
+++ b/traffic_updater/go/osrm_traffic_updater/get_telenav_traffic.go
@@ -0,0 +1,77 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+	"time"
+
+	"github.com/Telenav/osrm-backend/traffic_updater/go/gen-go/proxy"
+	"github.com/apache/thrift/lib/go/thrift"
+)
+
+func getTrafficFlow(ip string, port int, m map[int64]int, c chan<- bool) {
+	var transport thrift.TTransport
+	var err error
+
+	startTime := time.Now()
+
+	// make socket
+	targetServer := ip + ":" + strconv.Itoa(port)
+	fmt.Println("connect traffic proxy " + targetServer)
+	transport, err = thrift.NewTSocket(targetServer)
+	if err != nil {
+		fmt.Println("Error opening socket:", err)
+		c <- false
+		return
+	}
+
+	// Buffering
+	transport, err = thrift.NewTFramedTransportFactoryMaxLength(thrift.NewTTransportFactory(), 1024*1024*1024).GetTransport(transport)
+	if err != nil {
+		fmt.Println("Error get transport:", err)
+		c <- false
+		return
+	}
+	defer transport.Close()
+	if err := transport.Open(); err != nil {
+		fmt.Println("Error opening transport:", err)
+		c <- false
+		return
+	}
+
+	// protocol encoder&decoder
+	protocol := thrift.NewTCompactProtocolFactory().GetProtocol(transport)
+
+	// create proxy client
+	client := proxy.NewProxyServiceClient(thrift.NewTStandardClient(protocol, protocol))
+
+	// get flows
+	fmt.Println("getting flows")
+	var defaultCtx = context.Background()
+	var flows []*proxy.Flow
+	flows, err = client.GetAllFlows(defaultCtx)
+	if err != nil {
+		fmt.Println("get flows failed:", err)
+		c <- false
+		return
+	}
+	fmt.Printf("got flows count: %d\n", len(flows))
+
+	endTime := time.Now()
+	fmt.Printf("Processing time for getting traffic flow takes %f seconds\n", endTime.Sub(startTime).Seconds())
+
+	flows2map(flows, m)
+	endTime2 := time.Now()
+	fmt.Printf("Processing time for building traffic map takes %f seconds\n", endTime2.Sub(endTime).Seconds())
+
+	c <- true
+	return
+}
+
+func flows2map(flows []*proxy.Flow, m map[int64]int) {
+	for _, flow := range flows {
+		wayid := flow.WayId
+		m[wayid] = int(flow.Speed)
+	}
+}
diff --git a/traffic_updater/go/osrm_traffic_updater/osrm_speedtable_generator.go b/traffic_updater/go/osrm_traffic_updater/osrm_speedtable_generator.go
deleted file mode 100644
index 3dc5d54c5..000000000
--- a/traffic_updater/go/osrm_traffic_updater/osrm_speedtable_generator.go
+++ /dev/null
@@ -1,114 +0,0 @@
-package main
-
-import (
-	"bufio"
-	"fmt"
-	"log"
-	"os"
-	"strconv"
-	"strings"
-	"time"
-)
-
-// todo:
-//       Write data into more compressed format(parquet)
-//       Statistic to avoid unmatched element
-//       Multiple go routine for convert()
-func generateSpeedTable(wayid2speed map[uint64]int, way2nodeidsPath string, target string) {
-	startTime := time.Now()
-
-	// format is: wayid, nodeid, nodeid, nodeid...
-	source := make(chan string)
-	// format is fromid, toid, speed
-	sink := make(chan string)
-
-	go load(way2nodeidsPath, source)
-	go convert(source, sink, wayid2speed)
-	write(target, sink)
-
-	endTime := time.Now()
-	fmt.Printf("Processing time for generate speed table takes %f seconds\n", endTime.Sub(startTime).Seconds())
-}
-
-func load(mappingPath string, source chan<- string) {
-	defer close(source)
-
-	f, err := os.Open(mappingPath)
-	defer f.Close()
-	if err != nil {
-		log.Fatal(err)
-		fmt.Printf("Open idsmapping file of %v failed.\n", mappingPath)
-		return
-	}
-	fmt.Printf("Open idsmapping file of %s succeed.\n", mappingPath)
-
-	scanner := bufio.NewScanner(f)
-	for scanner.Scan() {
-		source <- (scanner.Text())
-	}
-}
-
-func convert(source <-chan string, sink chan<- string, wayid2speed map[uint64]int) {
-	var err error
-	defer close(sink)
-
-	for str := range source {
-		elements := strings.Split(str, ",")
-		if len(elements) < 3 {
-			fmt.Printf("Invalid string %s in wayid2nodeids mapping file\n", str)
-			continue
-		}
-
-		var wayid uint64
-		if wayid, err = strconv.ParseUint(elements[0], 10, 64); err != nil {
-			fmt.Printf("#Error during decoding wayid, row = %v\n", elements)
-			continue
-		}
-
-		if speed, ok := wayid2speed[wayid]; ok {
-			var nodes []string = elements[1:]
-			for i := 0; (i + 1) < len(nodes); i++ {
-				var n1, n2 uint64
-				if n1, err = strconv.ParseUint(nodes[i], 10, 64); err != nil {
-					fmt.Printf("#Error during decoding nodeid, row = %v\n", elements)
-					continue
-				}
-				if n2, err = strconv.ParseUint(nodes[i+1], 10, 64); err != nil {
-					fmt.Printf("#Error during decoding nodeid, row = %v\n", elements)
-					continue
-				}
-
-				var s string
-				if speed >= 0 {
-					s = fmt.Sprintf("%d,%d,%d\n", n1, n2, speed)
-				} else {
-					s = fmt.Sprintf("%d,%d,%d\n", n2, n1, -speed)
-				}
-
-				sink <- s
-			}
-		}
-	}
-}
-
-func write(targetPath string, sink chan string) {
-	outfile, err := os.OpenFile(targetPath, os.O_RDWR|os.O_CREATE, 0755)
-	defer outfile.Close()
-	defer outfile.Sync()
-	if err != nil {
-		log.Fatal(err)
-		fmt.Printf("Open output file of %s failed.\n", targetPath)
-		return
-	}
-	fmt.Printf("Open output file of %s succeed.\n", targetPath)
-
-	w := bufio.NewWriter(outfile)
-	defer w.Flush()
-	for str := range sink {
-		_, err := w.WriteString(str)
-		if err != nil {
-			log.Fatal(err)
-			return
-		}
-	}
-}
diff --git a/traffic_updater/go/osrm_traffic_updater/osrm_speedtable_generator_test.go b/traffic_updater/go/osrm_traffic_updater/osrm_speedtable_generator_test.go
deleted file mode 100644
index 58712c804..000000000
--- a/traffic_updater/go/osrm_traffic_updater/osrm_speedtable_generator_test.go
+++ /dev/null
@@ -1,72 +0,0 @@
-package main
-
-import (
-	"encoding/csv"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"log"
-	"os"
-	"strconv"
-	"strings"
-	"testing"
-)
-
-func TestGenerateSpeedTable(t *testing.T) {
-	wayid2speed := make(map[uint64]int)
-	loadMockTraffic("./testdata/mock-traffic.csv", wayid2speed)
-	generateSpeedTable(wayid2speed, "./testdata/id-mapping.csv", "./testdata/target.csv")
-
-	b1, err1 := ioutil.ReadFile("./testdata/target.csv")
-	if err1 != nil {
-		fmt.Print(err1)
-	}
-	str1 := string(b1)
-
-	b2, err2 := ioutil.ReadFile("./testdata/expect.csv")
-	if err2 != nil {
-		fmt.Print(err2)
-	}
-	str2 := string(b2)
-
-	if strings.Compare(str1, str2) != 0 {
-		t.Error("TestGenerateSpeedTable failed\n")
-	}
-}
-
-func loadMockTraffic(trafficPath string, wayid2speed map[uint64]int) {
-	// load mock traffic file
-	mockfile, err := os.Open(trafficPath)
-	defer mockfile.Close()
-	if err != nil {
-		log.Fatal(err)
-		fmt.Printf("Open pbf file of %v failed.\n", trafficPath)
-		return
-	}
-	fmt.Printf("Open pbf file of %s succeed.\n", trafficPath)
-
-	csvr := csv.NewReader(mockfile)
-	for {
-		row, err := csvr.Read()
-		if err != nil {
-			if err == io.EOF {
-				err = nil
-				break
-			} else {
-				fmt.Printf("Error during decoding mock traffic, row = %v\n", err)
-				return
-			}
-		}
-
-		var wayid uint64
-		var speed int64
-		if wayid, err = strconv.ParseUint(row[0], 10, 64); err != nil {
-			fmt.Printf("#Error during decoding wayid, row = %v\n", row)
-		}
-		if speed, err = strconv.ParseInt(row[1], 10, 32); err != nil {
-			fmt.Printf("#Error during decoding speed, row = %v\n", row)
-		}
-
-		wayid2speed[wayid] = (int)(speed)
-	}
-}
diff --git a/traffic_updater/go/osrm_traffic_updater/osrm_traffic_updater.go b/traffic_updater/go/osrm_traffic_updater/osrm_traffic_updater.go
index 4d9d084ba..33e2cd203 100644
--- a/traffic_updater/go/osrm_traffic_updater/osrm_traffic_updater.go
+++ b/traffic_updater/go/osrm_traffic_updater/osrm_traffic_updater.go
@@ -1,13 +1,8 @@
 package main
 
 import (
-	"context"
 	"flag"
 	"fmt"
-	"strconv"
-
-	"github.com/Telenav/osrm-backend/traffic_updater/go/gen-go/proxy"
-	"github.com/apache/thrift/lib/go/thrift"
 )
 
 var flags struct {
@@ -26,58 +21,42 @@ func init() {
 	flag.BoolVar(&flags.highPrecision, "d", false, "use high precision speeds, i.e. decimal")
 }
 
-func flows2map(flows []*proxy.Flow, m map[uint64]int) {
-	for _, flow := range flows {
-		wayid := (uint64)(flow.WayId)
-		m[wayid] = int(flow.Speed)
-	}
-}
+const TASKNUM = 128
+const CACHEDOBJECTS = 1000000
 
 func main() {
 	flag.Parse()
 
-	var transport thrift.TTransport
-	var err error
+	isFlowDoneChan := make(chan bool, 1)
+	wayid2speed := make(map[int64]int)
+	go getTrafficFlow(flags.ip, flags.port, wayid2speed, isFlowDoneChan)
 
-	// make socket
-	targetServer := flags.ip + ":" + strconv.Itoa(flags.port)
-	fmt.Println("connect traffic proxy " + targetServer)
-	transport, err = thrift.NewTSocket(targetServer)
-	if err != nil {
-		fmt.Println("Error opening socket:", err)
-		return
+	var sources [TASKNUM]chan string
+	for i := range sources {
+		sources[i] = make(chan string, CACHEDOBJECTS)
 	}
+	go loadWay2NodeidsTable(flags.mappingFile, sources)
 
-	// Buffering
-	transport, err = thrift.NewTFramedTransportFactoryMaxLength(thrift.NewTTransportFactory(), 1024*1024*1024).GetTransport(transport)
-	if err != nil {
-		fmt.Println("Error get transport:", err)
-		return
+	isFlowDone := wait4PreConditions(isFlowDoneChan)
+	if isFlowDone {
+		dumpSpeedTable4Customize(wayid2speed, sources, flags.csvFile)
 	}
-	defer transport.Close()
-	if err := transport.Open(); err != nil {
-		fmt.Println("Error opening transport:", err)
-		return
-	}
-
-	// protocol encoder&decoder
-	protocol := thrift.NewTCompactProtocolFactory().GetProtocol(transport)
-
-	// create proxy client
-	client := proxy.NewProxyServiceClient(thrift.NewTStandardClient(protocol, protocol))
-
-	// get flows
-	fmt.Println("getting flows")
-	var defaultCtx = context.Background()
-	flows, err := client.GetAllFlows(defaultCtx)
-	if err != nil {
-		fmt.Println("get flows failed:", err)
-		return
-	}
-	fmt.Printf("got flows count: %d\n", len(flows))
-
-	wayid2speed := make(map[uint64]int)
-	flows2map(flows, wayid2speed)
-
-	generateSpeedTable(wayid2speed, flags.mappingFile, flags.csvFile)
+}
+
+func wait4PreConditions(flowChan <-chan bool) (bool) {
+	var isFlowDone bool
+	loop:
+	for {
+		select {
+			case f := <- flowChan :
+				if !f {
+					fmt.Printf("[ERROR] Communication with traffic server failed.\n")
+					break loop
+				} else {
+					isFlowDone = true
+					break loop
+				}
+		}
+	}
+	return isFlowDone
 }
diff --git a/traffic_updater/go/osrm_traffic_updater/osrm_traffic_updater_test.go b/traffic_updater/go/osrm_traffic_updater/osrm_traffic_updater_test.go
new file mode 100644
index 000000000..a3348aa36
--- /dev/null
+++ b/traffic_updater/go/osrm_traffic_updater/osrm_traffic_updater_test.go
@@ -0,0 +1,35 @@
+package main
+
+import (
+	"testing"
+)
+
+func setChan2True(c chan<- bool) {
+	c <- true
+}
+
+func setChan2False(c chan<- bool) {
+	c <- false
+}
+
+func TestWait4AllPreconditions1(t *testing.T) {
+	c1 := make(chan bool, 1)
+
+	go setChan2True(c1)
+
+	b1 := wait4PreConditions(c1)
+	if !b1 {
+		t.Error("Testwait4AllPreconditions1 failed.\n")
+	}
+}
+
+func TestWait4AllPreconditions2(t *testing.T) {
+	c2 := make(chan bool, 1)
+
+	go setChan2False(c2)
+
+	b2 := wait4PreConditions(c2)
+	if b2 {
+		t.Error("Testwait4AllPreconditions1 failed.\n")
+	}
+}
diff --git a/traffic_updater/go/osrm_traffic_updater/speed_table_dumper.go b/traffic_updater/go/osrm_traffic_updater/speed_table_dumper.go
new file mode 100644
index 000000000..0a75b3c95
--- /dev/null
+++ b/traffic_updater/go/osrm_traffic_updater/speed_table_dumper.go
@@ -0,0 +1,127 @@
+package main
+
+import (
+	"os"
+	"log"
+	"fmt"
+	"bufio"
+	"sync"
+	"time"
+	"strings"
+	"strconv"
+)
+
+var tasksWg sync.WaitGroup
+var dumpFinishedWg sync.WaitGroup
+
+func dumpSpeedTable4Customize(wayid2speed map[int64]int, sources [TASKNUM]chan string, outputPath string) {
+	startTime := time.Now()
+
+	if len(wayid2speed) == 0 {
+		return
+	}
+
+	sink := make(chan string)
+	startTasks(wayid2speed, sources, sink)
+	startDump(outputPath, sink)
+	wait4AllTasksFinished(sink)
+
+	endTime := time.Now()
+	fmt.Printf("Processing time for dumpSpeedTable4Customize takes %f seconds\n", endTime.Sub(startTime).Seconds())
+}
+
+func startTasks(wayid2speed map[int64]int, sources [TASKNUM]chan string, sink chan<- string) {
+	tasksWg.Add(TASKNUM)
+	for i := 0; i < TASKNUM; i++ {
+		go task(wayid2speed, sources[i], sink)
+	}
+}
+
+func startDump(outputPath string, sink <-chan string) {
+	dumpFinishedWg.Add(1)
+	go write(outputPath, sink)
+}
+
+func wait4AllTasksFinished(sink chan string) {
+	tasksWg.Wait()
+	close(sink)
+	dumpFinishedWg.Wait()
+}
+
+func task(wayid2speed map[int64]int, source <-chan string, sink chan<- string) {
+	var err error
+	for str := range source {
+		elements := strings.Split(str, ",")
+		if len(elements) < 3 {
+			continue
+		}
+
+		var wayid uint64
+		if wayid, err = strconv.ParseUint(elements[0], 10, 64); err != nil {
+			fmt.Printf("#Error during decoding wayid, row = %v\n", elements)
+			continue
+		}
+
+		speedFwd, okFwd := wayid2speed[(int64)(wayid)]
+		speedBwd, okBwd := wayid2speed[(int64)(-wayid)]
+
+		if okFwd || okBwd {
+			var nodes []string = elements[1:]
+			for i := 0; (i + 1) < len(nodes); i++ {
+				var n1, n2 uint64
+				if n1, err = strconv.ParseUint(nodes[i], 10, 64); err != nil {
+					fmt.Printf("#Error during decoding nodeid, row = %v\n", elements)
+					continue
+				}
+				if n2, err = strconv.ParseUint(nodes[i+1], 10, 64); err != nil {
+					fmt.Printf("#Error during decoding nodeid, row = %v\n", elements)
+					continue
+				}
+				if okFwd {
+					sink <- generateSingleRecord(n1, n2, speedFwd, true)
+				}
+				if okBwd {
+					sink <- generateSingleRecord(n1, n2, speedBwd, false)
+				}
+				
+			}
+		}
+
+	}
+	tasksWg.Done() 
+}
+
+// format
+// if dir = true, means traffic for forward, generate: from, to, speed
+// if dir = false, means this speed is for backward flow, generate: to, from, speed
+func generateSingleRecord(from, to uint64, speed int, dir bool) (string){
+	if dir {
+		return fmt.Sprintf("%d,%d,%d\n", from, to, speed)
+	} else {
+		return fmt.Sprintf("%d,%d,%d\n", to, from, speed)
+	}
+}
+
+func write(targetPath string, sink <-chan string) {
+	outfile, err := os.OpenFile(targetPath, os.O_RDWR|os.O_CREATE, 0755)
+	defer outfile.Close()
+	defer outfile.Sync()
+	if err != nil {
+		log.Fatal(err)
+		fmt.Printf("Open output file of %s failed.\n", targetPath)
+		return
+	}
+	fmt.Printf("Open output file of %s succeed.\n", targetPath)
+
+	w := bufio.NewWriter(outfile)
+	defer w.Flush()
+	for str := range sink {
+		_, err := w.WriteString(str)
+		if err != nil {
+			log.Fatal(err)
+			return
+		}
+	}
+
+	dumpFinishedWg.Done()
+}
diff --git a/traffic_updater/go/osrm_traffic_updater/speed_table_dumper_test.go b/traffic_updater/go/osrm_traffic_updater/speed_table_dumper_test.go
new file mode 100644
index 000000000..48dd6188f
--- /dev/null
+++ b/traffic_updater/go/osrm_traffic_updater/speed_table_dumper_test.go
@@ -0,0 +1,169 @@
+package main
+
+import (
+	"testing"
+	"os"
+	"log"
+	"fmt"
+	"strconv"
+	"io"
+	"encoding/csv"
+	"io/ioutil"
+	"strings"
+	"reflect"
+
+	"github.com/Telenav/osrm-backend/traffic_updater/go/gen-go/proxy"
+)
+
+func TestSpeedTableDumper1(t *testing.T) {
+	// load result into sources
+	var sources [TASKNUM]chan string
+	for i := range sources {
+		sources[i] = make(chan string, 10000)
+	}
+	go loadWay2NodeidsTable("./testdata/id-mapping.csv.snappy", sources)
+
+	// construct mock traffic
+	var flows []*proxy.Flow
+	flows = loadMockTraffic("./testdata/mock-traffic.csv", flows)
+	wayid2speed := make(map[int64]int)
+	flows2map(flows, wayid2speed)
+
+	dumpSpeedTable4Customize(wayid2speed, sources, "./testdata/target.csv")
+
+	compareFileContentUnstable("./testdata/target.csv", "./testdata/expect.csv", t)
+}
+
+func TestGenerateSingleRecord1(t *testing.T) {
+	str := generateSingleRecord(12345, 54321, 33, true)
+	if strings.Compare(str, "12345,54321,33\n") != 0 {
+		t.Error("Test GenerateSingleRecord failed.\n")
+	}
+}
+
+func TestGenerateSingleRecord2(t *testing.T) {
+	str := generateSingleRecord(12345, 54321, 33, false)
+	if strings.Compare(str, "54321,12345,33\n") != 0 {
+		t.Error("Test GenerateSingleRecord failed.\n")
+	}
+}
+
+func loadMockTraffic(trafficPath string, flows []*proxy.Flow) []*proxy.Flow {
+	// load mock traffic file
+	mockfile, err := os.Open(trafficPath)
+	defer mockfile.Close()
+	if err != nil {
+		log.Fatal(err)
+		fmt.Printf("Open pbf file of %v failed.\n", trafficPath)
+		return nil
+	}
+	fmt.Printf("Open pbf file of %s succeed.\n", trafficPath)
+
+	csvr := csv.NewReader(mockfile)
+	for {
+		row, err := csvr.Read()
+		if err != nil {
+			if err == io.EOF {
+				err = nil
+				break
+			} else {
+				fmt.Printf("Error during decoding mock traffic, err = %v\n", err)
+				return nil
+			}
+		}
+
+		var wayid int64
+		var speed int64
+		if wayid, err = strconv.ParseInt(row[0], 10, 64); err != nil {
+			fmt.Printf("#Error during decoding wayid, row = %v\n", row)
+		}
+		if speed, err = strconv.ParseInt(row[1], 10, 32); err != nil {
+			fmt.Printf("#Error during decoding speed, row = %v\n", row)
+		}
+
+		var flow proxy.Flow
+		flow.WayId = wayid
+		flow.Speed = (float64)(speed)
+		flows = append(flows, &flow)
+	}
+	return flows
+}
+
+type tNodePair struct {
+	f, t uint64
+}
+
+func loadSpeedCsv(f string, m map[tNodePair]int) {
+		// load mock traffic file
+		mockfile, err := os.Open(f)
+		defer mockfile.Close()
+		if err != nil {
+			log.Fatal(err)
+			fmt.Printf("Open file of %v failed.\n", f)
+			return
+		}
+		fmt.Printf("Open file of %s succeed.\n", f)
+
+		csvr := csv.NewReader(mockfile)
+		for {
+			row, err := csvr.Read()
+			if err != nil {
+				if err == io.EOF {
+					err = nil
+					break
+				} else {
+					fmt.Printf("Error during decoding file %s, err = %v\n", f, err)
+					return
+				}
+			}
+
+			var from, to uint64
+			var speed int
+			if from, err = strconv.ParseUint(row[0], 10, 64); err != nil {
+				fmt.Printf("#Error during decoding, row = %v\n", row)
+				return
+			}
+			if to, err = strconv.ParseUint(row[1], 10, 64); err != nil {
+				fmt.Printf("#Error during decoding, row = %v\n", row)
+				return
+			}
+			if speed, err = strconv.Atoi(row[2]); err != nil {
+				fmt.Printf("#Error during decoding, row = %v\n", row)
+				return
+			}
+
+			m[tNodePair{from, to}] = speed
+		}
+}
+
+func compareFileContentStable(f1, f2 string, t *testing.T) {
+	b1, err1 := ioutil.ReadFile(f1)
+	if err1 != nil {
+		fmt.Print(err1)
+	}
+	str1 := string(b1)
+
+	b2, err2 := ioutil.ReadFile(f2)
+	if err2 != nil {
+		fmt.Print(err2)
+	}
+	str2 := string(b2)
+
+	if strings.Compare(str1, str2) != 0 {
+		t.Error("Compare file content failed\n")
+	}
+}
+
+func compareFileContentUnstable(f1, f2 string, t *testing.T) {
+	r1 := make(map[tNodePair]int)
+	loadSpeedCsv(f1, r1)
+
+	r2 := make(map[tNodePair]int)
+	loadSpeedCsv(f2, r2)
+
+	eq := reflect.DeepEqual(r1, r2)
+	if !eq {
+		t.Error("TestLoadWay2Nodeids failed to generate correct map\n")
+	}
+}
+
diff --git a/traffic_updater/go/osrm_traffic_updater/testdata/expect.csv b/traffic_updater/go/osrm_traffic_updater/testdata/expect.csv
index 4c95ae579..1c91e2e23 100755
--- a/traffic_updater/go/osrm_traffic_updater/testdata/expect.csv
+++ b/traffic_updater/go/osrm_traffic_updater/testdata/expect.csv
@@ -1,6 +1,7 @@
 84760891102,19496208102,81
-84762609102,244183320001101,87
-244183320001101,84762607102,87
+244183320001101,84762609102,87
+84762607102,244183320001101,87
 84760849102,84760850102,47
 84760858102,84760846102,59
-847608599102,84760858102,59
+84762609102,244183320001101,87
+244183320001101,84762607102,87
diff --git a/traffic_updater/go/osrm_traffic_updater/testdata/id-mapping-delta.csv b/traffic_updater/go/osrm_traffic_updater/testdata/id-mapping-delta.csv
new file mode 100755
index 000000000..326436f3c
--- /dev/null
+++ b/traffic_updater/go/osrm_traffic_updater/testdata/id-mapping-delta.csv
@@ -0,0 +1,4 @@
+24418325,84760891102,-65264683000
+7,1718000,244098557391999,-244098557393999
+11,-1760000,1000
+1,-3000,12000
\ No newline at end of file
diff --git a/traffic_updater/go/osrm_traffic_updater/testdata/id-mapping-delta.csv.snappy b/traffic_updater/go/osrm_traffic_updater/testdata/id-mapping-delta.csv.snappy
new file mode 100755
index 000000000..53b828c98
Binary files /dev/null and b/traffic_updater/go/osrm_traffic_updater/testdata/id-mapping-delta.csv.snappy differ
diff --git a/traffic_updater/go/osrm_traffic_updater/testdata/id-mapping.csv b/traffic_updater/go/osrm_traffic_updater/testdata/id-mapping.csv
index 6d942a1bc..94063b4e7 100755
--- a/traffic_updater/go/osrm_traffic_updater/testdata/id-mapping.csv
+++ b/traffic_updater/go/osrm_traffic_updater/testdata/id-mapping.csv
@@ -1,4 +1,4 @@
 24418325,84760891102,19496208102
 24418332,84762609102,244183320001101,84762607102
 24418343,84760849102,84760850102
-24418344,84760846102,84760858102,847608599102
\ No newline at end of file
+24418344,84760846102,84760858102
\ No newline at end of file
diff --git a/traffic_updater/go/osrm_traffic_updater/testdata/id-mapping.csv.snappy b/traffic_updater/go/osrm_traffic_updater/testdata/id-mapping.csv.snappy
new file mode 100755
index 000000000..e33eea19c
Binary files /dev/null and b/traffic_updater/go/osrm_traffic_updater/testdata/id-mapping.csv.snappy differ
diff --git a/traffic_updater/go/osrm_traffic_updater/testdata/mock-traffic.csv b/traffic_updater/go/osrm_traffic_updater/testdata/mock-traffic.csv
index 8a8ce40d4..25bc19235 100755
--- a/traffic_updater/go/osrm_traffic_updater/testdata/mock-traffic.csv
+++ b/traffic_updater/go/osrm_traffic_updater/testdata/mock-traffic.csv
@@ -1,4 +1,5 @@
 24418325,81
+-24418332,87
 24418332,87
 24418343,47
-24418344,-59
\ No newline at end of file
+-24418344,59
\ No newline at end of file
diff --git a/traffic_updater/go/osrm_traffic_updater/testdata/target.csv b/traffic_updater/go/osrm_traffic_updater/testdata/target.csv
index 4c95ae579..01fa83ad2 100755
--- a/traffic_updater/go/osrm_traffic_updater/testdata/target.csv
+++ b/traffic_updater/go/osrm_traffic_updater/testdata/target.csv
@@ -1,6 +1,7 @@
-84760891102,19496208102,81
-84762609102,244183320001101,87
-244183320001101,84762607102,87
-84760849102,84760850102,47
 84760858102,84760846102,59
-847608599102,84760858102,59
+84762609102,244183320001101,87
+84760849102,84760850102,47
+84760891102,19496208102,81
+244183320001101,84762609102,87
+244183320001101,84762607102,87
+84762607102,244183320001101,87
diff --git a/traffic_updater/go/osrm_traffic_updater/way2nodeids_loader.go b/traffic_updater/go/osrm_traffic_updater/way2nodeids_loader.go
new file mode 100644
index 000000000..8aa87a497
--- /dev/null
+++ b/traffic_updater/go/osrm_traffic_updater/way2nodeids_loader.go
@@ -0,0 +1,58 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"time"
+	"github.com/golang/snappy"
+)
+
+func loadWay2NodeidsTable(filepath string, sources [TASKNUM]chan string) {
+	startTime := time.Now()
+
+	data := make(chan string)
+	go load(filepath, data)
+	convert(data, sources)
+
+	endTime := time.Now()
+	fmt.Printf("Processing time for loadWay2NodeidsTable takes %f seconds\n", endTime.Sub(startTime).Seconds())
+}
+
+func load(mappingPath string, data chan<- string) {
+	defer close(data)
+
+	f, err := os.Open(mappingPath)
+	defer f.Close()
+	if err != nil {
+		log.Fatal(err)
+		fmt.Printf("Open idsmapping file of %v failed.\n", mappingPath)
+		return
+	}
+	fmt.Printf("Open idsmapping file of %s succeed.\n", mappingPath)
+
+	scanner := bufio.NewScanner(snappy.NewReader(f))
+	for scanner.Scan() {
+		data <- (scanner.Text())
+	}
+} 
+
+
+// input data format
+// wayid1, n1, n2
+// wayid2, n3, n4, n5
+func convert(data <-chan string, sources [TASKNUM]chan string) {
+	for i := range sources {
+		defer close(sources[i])
+	}
+
+	var count int
+	for str := range data {
+		chanIndex := count % TASKNUM
+		count++
+		sources[chanIndex] <- str
+	}
+}
+
+
diff --git a/traffic_updater/go/osrm_traffic_updater/way2nodeids_loader_test.go b/traffic_updater/go/osrm_traffic_updater/way2nodeids_loader_test.go
new file mode 100644
index 000000000..cdf608c86
--- /dev/null
+++ b/traffic_updater/go/osrm_traffic_updater/way2nodeids_loader_test.go
@@ -0,0 +1,64 @@
+package main
+
+import (
+	"testing"
+	"reflect"
+	"sync"
+)
+
+
+func TestLoadWay2Nodeids(t *testing.T) {
+	// load result into sources
+	var sources [TASKNUM]chan string
+	for i := range sources {
+		//fmt.Printf("&&& current i is %d\n", i)
+		sources[i] = make(chan string, 10000)
+	}
+	go loadWay2NodeidsTable("./testdata/id-mapping.csv.snappy", sources)
+
+	allWay2NodesChan := make(chan string, 10000)
+	var wgs sync.WaitGroup
+	wgs.Add(TASKNUM)
+	for i:= 0; i < TASKNUM; i++ {
+		//fmt.Printf("### current i is %d\n", i)
+		go mergeChannels(sources[i], allWay2NodesChan, &wgs)
+	}
+	wgs.Wait()
+
+	// dump result into map
+	way2nodeids := make(map[string]bool)
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		for elem := range allWay2NodesChan {
+			way2nodeids[elem] = true
+		}
+		wg.Done()
+	}()
+	close(allWay2NodesChan)
+	wg.Wait()
+
+	// test map result
+	way2nodeidsExpect := make(map[string]bool)
+	generateMockWay2nodeids(way2nodeidsExpect)
+
+	eq := reflect.DeepEqual(way2nodeids, way2nodeidsExpect)
+	if !eq {
+		t.Error("TestLoadWay2Nodeids failed to generate correct map\n")
+	}
+}
+
+func mergeChannels(f <-chan string, t chan<- string, w *sync.WaitGroup) {
+	for elem := range f {
+		t <- elem
+	}
+	w.Done()
+}
+
+func generateMockWay2nodeids(way2nodeids map[string]bool) {
+	way2nodeids["24418325,84760891102,19496208102"] = true
+	way2nodeids["24418332,84762609102,244183320001101,84762607102"] = true
+	way2nodeids["24418343,84760849102,84760850102"] = true
+	way2nodeids["24418344,84760846102,84760858102"] = true
+}
+
diff --git a/traffic_updater/go/snappy_command/snappy_command.go b/traffic_updater/go/snappy_command/snappy_command.go
new file mode 100644
index 000000000..0842bb2e0
--- /dev/null
+++ b/traffic_updater/go/snappy_command/snappy_command.go
@@ -0,0 +1,64 @@
+package main
+
+import (
+	"flag"
+	"strings"
+	"fmt"
+	"os"
+	"io"
+	"github.com/golang/snappy"
+)
+
+const snappySuffix string = ".snappy"
+
+var flags struct {
+	input        string
+	output       string
+	suffix       string
+}
+
+func init() {
+	flag.StringVar(&flags.input, "i", "", "Input file.")
+	flag.StringVar(&flags.output, "o", "", "Output file.")
+}
+
+func main() {
+	flag.Parse()
+
+	inputCompressed := strings.HasSuffix(flags.input, snappySuffix)
+	outputCompressed := strings.HasSuffix(flags.output, snappySuffix)
+
+	if inputCompressed == outputCompressed {
+		fmt.Printf("Error. Input and output must have one with .snappy suffix and one without.\n")
+		return
+	}
+
+	fi, err1 := os.Open(flags.input)
+	if err1 != nil {
+		fmt.Printf("Open input file failed.\n")
+		return
+	}
+	defer fi.Close()
+
+	fo, err2 := os.OpenFile(flags.output, os.O_RDWR|os.O_CREATE, 0755)
+	if err2 != nil {
+		fmt.Printf("Open output file failed.\n")
+		return
+	}
+	defer fo.Close()
+	defer fo.Sync()
+
+	buf := make([]byte, 128 * 1024)
+	if inputCompressed {
+		_, err := io.CopyBuffer(fo, snappy.NewReader(fi), buf)	
+		if err != nil {
+			fmt.Printf("Decompression failed\n")
+		}
+	} else {
+		_, err := io.CopyBuffer(snappy.NewWriter(fo), fi, buf)
+		if err != nil {
+			fmt.Printf("Compression failed\n")
+		}
+	}
+
+}
diff --git a/traffic_updater/go/wayid2nodeid_extractor/wayid2nodeids_extractor.go b/traffic_updater/go/wayid2nodeid_extractor/wayid2nodeids_extractor.go
index ba7a3ceb7..306add1ee 100644
--- a/traffic_updater/go/wayid2nodeid_extractor/wayid2nodeids_extractor.go
+++ b/traffic_updater/go/wayid2nodeid_extractor/wayid2nodeids_extractor.go
@@ -156,3 +156,4 @@ func main() {
 	endTime := time.Now()
 	fmt.Printf("Total processing time for wayid2nodeids-extract takes %f seconds\n", endTime.Sub(startTime).Seconds())
 }
+