Setting up Page objects in Protractor

I am new to protractor and making my hand dirty with all the various tips and tricks to make my code more modular and efficient enough. I create a page object for my specification file. Page object:

var mapFeedBackpage=function(){

    REPORT_ROAD=element.all(by.css("div[ng-click=\"setLocation('report_road')\"]"));
    ROAD_NEW=element.all(by.css("div[ ng-click=\"mapFeedBack.editObject= mapFeedBack.createMapObjectModel();setLocation(mapFeedBack.noMap?'road_new':'choose_location_road_new/road_new')\"]"));
    ZOOM_IN=element(by.css('div[ng-click="zoomIn()"]'));
    ROAD_NAME=element(by.model("mapFeedBack.editObject.roadName"));
    SUBMIT_ROAD=element(by.css('button[ng-click="onSubmit({reportType: reportType})"]'));
    HIGHWAY_OPTION=element(by.model("mapFeedBack.editObject[attrs.select].selected")).$("[value='string:app.road.roadType.highway']");


    };

    module.exports=mapFeedBackpage;

Now the problem is that when i write this.REPORT_ROAD in the page load file my test fails saying it cant find the REPORT_ROAD variable but when I remove this for the variable it works. Now, I am wondering why is that so? Can anyone please explain me this? I used the Page Load guide : http://ift.tt/29f0hNU

My Spec file code is as follows :

var mapFeedBackpage=require('./mapFeedBack-page.js')
describe("Map feedback Automation",function()
{

var mapFeedBack= new mapFeedBackpage();

    it("Check if the Url works ",function() //spec1
    {
        browser.get(browser.params.url);
        expect(browser.getCurrentUrl()).toContain("report");
        browser.sleep(browser.params.sleeptime);
    }); 


    it("test browser should reach report road option",function() //spec2s
    {
        REPORT_ROAD.click();
        expect(browser.getCurrentUrl()).toContain("report_road");
        browser.sleep(browser.params.sleeptime);
        browser.sleep(browser.params.sleeptime);
    });


    it("test browser should reach report road missing",function() //spec3
    {
        ROAD_NEW.click();
        expect(browser.getCurrentUrl()).toContain("choose_location_road_new/road_new");
        browser.sleep(browser.params.sleeptime);
        browser.sleep(browser.params.sleeptime);
    });


    it("test browser should zoom on map ",function() //spec4
    {


    var EC = protractor.ExpectedConditions;

    for(var i=0;i<3;i++)
    {
        var elm = ZOOM_IN;
        browser.wait(EC.elementToBeClickable(elm), 10000);
        elm.click();
        browser.sleep(browser.params.sleeptime);
    }



    }); 

    it("Should click on ok option",function() //spec5
    {
            var EC = protractor.ExpectedConditions;
        var elm = element(by.buttonText('OK'));
        browser.wait(EC.elementToBeClickable(elm), 10000);
        elm.click();

        expect(browser.getCurrentUrl()).toContain("road_new");

    }); 



it("test browser should reach report road option",function() //spec6
    {

        browser.sleep(browser.params.sleeptime);
        expect(browser.getCurrentUrl()).toContain("road_new");

    }); 



    it("should  enter a road name",function()   //spec8
    {       

     browser.sleep(browser.params.sleeptime);

     var testroadname = browser.params.testroadname;


     ROAD_NAME.sendKeys(testroadname);
    browser.sleep(browser.params.sleeptime);



    });


        it("should check the type of road is highway",function()  //spec9
    {

    HIGHWAY_OPTION.click();
});


        it("should  submmit the map feedback",function()  //spec10
    {       

    SUBMIT_ROAD.click();
    browser.sleep(browser.params.sleeptime);
    });





});