Segment Information (Details) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments			2
Revenue	$ 3,893	$ 3,475	$ 6,903	$ 6,559
Gross profit	3,192	2,677	5,755	5,127
Amortization of intangible assets	120	90	231	180
Intangible assets	3,356	3,181	3,356	3,181
Intersection [Member]
Segment Reporting Information [Line Items]
Revenue	2,842	2,214	5,259	4,118
Gross profit	2,596	1,954	4,782	3,689
Amortization of intangible assets	92	90	184	180
Intangible assets	2,293	2,635	2,293	2,635
Highway [Member]
Segment Reporting Information [Line Items]
Revenue	1,051	1,261	1,644	2,441
Gross profit	596	723	973	1,438
Amortization of intangible assets	28	0	47	0
Intangible assets	$ 1,063	$ 546	$ 1,063	$ 546

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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